diff --git a/main/admin/skills_import.php b/main/admin/skills_import.php
index fb097aa347..bd2dab5b98 100644
--- a/main/admin/skills_import.php
+++ b/main/admin/skills_import.php
@@ -14,7 +14,6 @@ $cidReset = true;
 require '../inc/global.inc.php';
 require_once api_get_path(LIBRARY_PATH).'mail.lib.inc.php';
 require_once api_get_path(LIBRARY_PATH).'fileManage.lib.php';
-require_once api_get_path(LIBRARY_PATH).'classmanager.lib.php';
 require_once api_get_path(LIBRARY_PATH).'import.lib.php';
 
 function validate_data($skills) {
@@ -282,16 +281,13 @@ if ($count_fields > 0) {
 		$i++;
 	}
 }
-
 ?>
 <p><?php echo get_lang('CSVMustLookLike').' ('.get_lang('MandatoryFields').')'; ?> :</p>
 
-<blockquote>
 <pre>
-<b>id</b>;<b>parent_id</b>;<b>name</b>;<b>description</b><br />
-<b>n</b>;<b>m</b>;<b>xxx</b>;xxx<br />
+    <b>id</b>;<b>parent_id</b>;<b>name</b>;<b>description</b>
+    <b>2</b>;<b>0</b>;<b>Chamilo Expert</b>;Chamilo is an open source LMS;<br />
 </pre>
-</blockquote>
 
 <!--p><?php echo get_lang('XMLMustLookLike').' ('.get_lang('MandatoryFields').')'; ?> :</p>
 
diff --git a/main/admin/skills_wheel.php b/main/admin/skills_wheel.php
index 8725bfd236..f173dce952 100644
--- a/main/admin/skills_wheel.php
+++ b/main/admin/skills_wheel.php
@@ -22,6 +22,7 @@ if (api_get_setting('allow_skills_tool') != 'true') {
 
 //Adds the JS needed to use the jqgrid
 $htmlHeadXtra[] = api_get_js('d3.v2.min.js');
+$htmlHeadXtra[] = api_get_js('coffeewheel/wheel.js');
 
 $skill  = new Skill();
 $type   = 'edit'; //edit
@@ -31,16 +32,14 @@ $type   = 'edit'; //edit
 //$html = $skill_visualizer->return_html();
 //$url  = api_get_path(WEB_AJAX_PATH).'skill.ajax.php?1=1';
 
+
+
 $tpl = new Template(null, false, false);
 
 //$tpl->assign('url', $url);
 //$tpl->assign('html', $html);
-$tpl->assign('html', api_get_js('coffeewheel/wheel.js'));
-//$tpl->assign('skill_visualizer', $skill_visualizer);
 //$tpl->assign('js', $skill_visualizer->return_js());
-//$tpl->assign('js', api_get_js('coffeewheel/wheel.js'));
 
-//
 $content = $tpl->fetch('default/skill/skill_wheel.tpl');
 $tpl->assign('content', $content);
-$tpl->display_no_layout_template();
+$tpl->display_no_layout_template();
\ No newline at end of file
diff --git a/main/inc/lib/javascript/coffeewheel/wheel.js b/main/inc/lib/javascript/coffeewheel/wheel.js
index f5bf9ee69a..bdd4ac1f04 100644
--- a/main/inc/lib/javascript/coffeewheel/wheel.js
+++ b/main/inc/lib/javascript/coffeewheel/wheel.js
@@ -1,6 +1,8 @@
 /* Define constants and size of the wheel */
-    /** Total width of the wheel (also counts for the height) */
-var w = 800,
+/** Total width of the wheel (also counts for the height) */
+
+$(document).ready(function() {    
+    var w = 800,
     h = w,
     r = w / 2,
     /** x/y positionning of the center of the wheel */
@@ -12,148 +14,190 @@ var w = 800,
     duration = 1000,
     /** Levels to show */
     l = 3;
-/* Locate the #div id element */
-var div = d3.select("#vis");
-/* Remove the image (make way for the dynamic stuff */
-div.select("img").remove();
-/* Append an element "svg" to the #vis section */
-var vis = div.append("svg")
+        
+    /* Locate the #div id element */
+    var div = d3.select("#vis");
+    
+    /* Remove the image (make way for the dynamic stuff */
+    div.select("img").remove();
+    
+    /* Append an element "svg" to the #vis section */
+    var vis = div.append("svg")
     .attr("width", w + p * 2)
     .attr("height", h + p * 2)
     .append("g")
     .attr("transform", "translate(" + (r + p) + "," + (r/1.5 + p) + ")"); 
-/* ...update translate variables to change coordinates of wheel's center */
-/* Add a small label to help the user */
-div.append("p")
+        
+    /* ...update translate variables to change coordinates of wheel's center */
+    /* Add a small label to help the user */
+    div.append("p")
     .attr("id", "intro")
     .text("Click to zoom!");
-/* Generate the partition layout */
-var partition = d3.layout.partition()
+        
+    /* Generate the partition layout */
+    var partition = d3.layout.partition()
     .sort(null)
     /** Value here seems to be a calculation of the size of the elements
-        depending on the level of depth they're at. Changing it makes
-        elements pass over the limits of others... */
-    .value(function(d) { return 5.8 - d.depth; });
-/* Generate an arc which will define the whole wheel context */
-var arc = d3.svg.arc()
-    .startAngle(function(d) { return Math.max(0, Math.min(2 * Math.PI, x(d.x))); })
-    .endAngle(function(d) { return Math.max(0, Math.min(2 * Math.PI, x(d.x + d.dx))); })
-    .innerRadius(function(d) { return Math.max(0, d.y ? y(d.y) : d.y); })
-    .outerRadius(function(d) { return Math.max(0, y(d.y + d.dy)); });
-/* ...adding "+1" to "y" function's params is really funny */
-/* Exexute the calculation based on a JSON file provided */
-/*d3.json("wheel.json", function(json) {*/
-/** Get the JSON list of skills and work on it */
-d3.json("skills.json.php", function(json) {
-  /** Define the list of nodes based on the JSON */
-  var nodes = partition.nodes({children: json});
+            depending on the level of depth they're at. Changing it makes
+            elements pass over the limits of others... */
+    .value(function(d) {
+        return 5.8 - d.depth;
+    });
+        
+    /* Generate an arc which will define the whole wheel context */
+    var arc = d3.svg.arc()
+    .startAngle(function(d) {
+        return Math.max(0, Math.min(2 * Math.PI, x(d.x)));
+    })
+    .endAngle(function(d) {
+        return Math.max(0, Math.min(2 * Math.PI, x(d.x + d.dx)));
+    })
+    .innerRadius(function(d) {
+        return Math.max(0, d.y ? y(d.y) : d.y);
+    })
+    .outerRadius(function(d) {
+        return Math.max(0, y(d.y + d.dy));
+    });
+        
+    /* ...adding "+1" to "y" function's params is really funny */
+    /* Exexute the calculation based on a JSON file provided */
+    /*d3.json("wheel.json", function(json) {*/
+    /** Get the JSON list of skills and work on it */
+    
+    d3.json("skills.json.php", function(json) {
+        /** Define the list of nodes based on the JSON */
+        var nodes = partition.nodes({
+            children: json
+        });
 
-  var path = vis.selectAll("path").data(nodes);
-  path.enter().append("path")
-      .attr("id", function(d, i) { return "path-" + i; })
-      .attr("d", arc)
-      .attr("fill-rule", "evenodd")
-      .style("fill", colour)
-      .on("click", click);
+        var path = vis.selectAll("path").data(nodes);
+        
+        path.enter().append("path")
+        .attr("id", function(d, i) {
+            return "path-" + i;
+        })
+        .attr("d", arc)
+        .attr("fill-rule", "evenodd")
+        .style("fill", colour)
+        .on("click", click);
 
-  var text = vis.selectAll("text").data(nodes);
-  var textEnter = text.enter().append("text")
-      .style("fill-opacity", 1)
-      .style("fill", function(d) {
-        return brightness(d3.rgb(colour(d))) < 125 ? "#eee" : "#000";
-      })
-      .attr("text-anchor", function(d) {
-        return x(d.x + d.dx / 2) > Math.PI ? "end" : "start";
-      })
-      .attr("dy", ".2em")
-      .attr("transform", function(d) {
-        /** Get the text details and define the rotation and general position */
-        var multiline = (d.name || "").split(" ").length > 1,
+        var text = vis.selectAll("text").data(nodes);
+        var textEnter = text.enter().append("text")
+        .style("fill-opacity", 1)
+        .style("fill", function(d) {
+            return brightness(d3.rgb(colour(d))) < 125 ? "#eee" : "#000";
+        })
+        .attr("text-anchor", function(d) {
+            return x(d.x + d.dx / 2) > Math.PI ? "end" : "start";
+        })
+        .attr("dy", ".2em")
+        .attr("transform", function(d) {
+            /** Get the text details and define the rotation and general position */
+            var multiline = (d.name || "").split(" ").length > 1,
             angle = x(d.x + d.dx / 2) * 180 / Math.PI - 90,
             rotate = angle + (multiline ? -.5 : 0);
-        return "rotate(" + rotate + ")translate(" + (y(d.y) + p) + ")rotate(" + (angle > 90 ? -180 : 0) + ")";
-      })
-      .on("click", click);
-  /** Managing text - alway maximum two words */
-  textEnter.append("tspan")
-      .attr("x", 0)
-      .text(function(d) { return d.depth ? d.name.split(" ")[0] : ""; });
-  textEnter.append("tspan")
-      .attr("x", 0)
-      .attr("dy", "1em")
-      .text(function(d) { return d.depth ? d.name.split(" ")[1] || "" : ""; });
+            return "rotate(" + rotate + ")translate(" + (y(d.y) + p) + ")rotate(" + (angle > 90 ? -180 : 0) + ")";
+        })
+        .on("click", click);
+          
+        /** Managing text - alway maximum two words */
+        textEnter.append("tspan")
+        .attr("x", 0)
+        .text(function(d) {
+            return d.depth ? d.name.split(" ")[0] : "";
+        });
+        textEnter.append("tspan")
+        .attr("x", 0)
+        .attr("dy", "1em")
+        .text(function(d) {
+            return d.depth ? d.name.split(" ")[1] || "" : "";
+        });
+
+
+    });
+});
+
 
-  function click(d) {
+
+function click(d) {
     path.transition()
-      .duration(duration)
-      .attrTween("d", arcTween(d));
+    .duration(duration)
+    .attrTween("d", arcTween(d));
 
     // Somewhat of a hack as we rely on arcTween updating the scales.
-    text
-      .style("visibility", function(e) {
+    text.style("visibility", function(e) {
         return isParentOf(d, e) ? null : d3.select(this).style("visibility");
-      })
-      .transition().duration(duration)
-      .attrTween("text-anchor", function(d) {
+    })
+    .transition().duration(duration)
+    .attrTween("text-anchor", function(d) {
         return function() {
-          return x(d.x + d.dx / 2) > Math.PI ? "end" : "start";
+            return x(d.x + d.dx / 2) > Math.PI ? "end" : "start";
         };
-      })
-      .attrTween("transform", function(d) {
+    })
+    .attrTween("transform", function(d) {
         var multiline = (d.name || "").split(" ").length > 1;
         return function() {
-          var angle = x(d.x + d.dx / 2) * 180 / Math.PI - 90,
-              rotate = angle + (multiline ? -.5 : 0);
-          return "rotate(" + rotate + ")translate(" + (y(d.y) + p) + ")rotate(" + (angle > 90 ? -180 : 0) + ")";
+            var angle = x(d.x + d.dx / 2) * 180 / Math.PI - 90,
+            rotate = angle + (multiline ? -.5 : 0);
+            return "rotate(" + rotate + ")translate(" + (y(d.y) + p) + ")rotate(" + (angle > 90 ? -180 : 0) + ")";
         };
-      })
-      .style("fill-opacity", function(e) { return isParentOf(d, e) ? 1 : 1e-6; })
-      .each("end", function(e) {
+    })
+    .style("fill-opacity", function(e) {
+        return isParentOf(d, e) ? 1 : 1e-6;
+    })
+    .each("end", function(e) {
         d3.select(this).style("visibility", isParentOf(d, e) ? null : "hidden");
-      });
-  }
-});
+    });
+}
+
+
 /* Returns whether p is parent of c */
 function isParentOf(p, c) {
-  if (p === c) return true;
-  if (p.children) {
-    return p.children.some(function(d) {
-      return isParentOf(d, c);
-    });
-  }
-  return false;
+    if (p === c) return true;
+    if (p.children) {
+        return p.children.some(function(d) {
+            return isParentOf(d, c);
+        });
+    }
+    return false;
 }
+
 /* Generated random colour */
 function colour(d) {
-  if (d.children) {
-    // There is a maximum of two children!
-    var colours = d.children.map(colour),
+    if (d.children) {
+        // There is a maximum of two children!
+        var colours = d.children.map(colour),
         a = d3.hsl(colours[0]),
         b = d3.hsl(colours[1]);
-    // L*a*b* might be better here...
-    return d3.hsl((a.h + b.h) / 2, a.s * 1.2, a.l / 1.2);
-  }
-  return d.colour || "#fff";
+        // L*a*b* might be better here...
+        return d3.hsl((a.h + b.h) / 2, a.s * 1.2, a.l / 1.2);
+    }
+    return d.colour || "#fff";
 }
 
 /* Interpolate the scales! */
 function arcTween(d) {
-  var my = maxY(d),
-      xd = d3.interpolate(x.domain(), [d.x, d.x + d.dx]),
-      yd = d3.interpolate(y.domain(), [d.y, my]),
-      yr = d3.interpolate(y.range(), [d.y ? 20 : 0, r]);
-  return function(d) {
-    return function(t) { x.domain(xd(t)); y.domain(yd(t)).range(yr(t)); return arc(d); };
-  };
+    var my = maxY(d),
+    xd = d3.interpolate(x.domain(), [d.x, d.x + d.dx]),
+    yd = d3.interpolate(y.domain(), [d.y, my]),
+    yr = d3.interpolate(y.range(), [d.y ? 20 : 0, r]);
+    return function(d) {
+        return function(t) {
+            x.domain(xd(t));
+            y.domain(yd(t)).range(yr(t));
+            return arc(d);
+        };
+    };
 }
+
 /*  */
 function maxY(d) {
-  return d.children ? Math.max.apply(Math, d.children.map(maxY)) : d.y + d.dy;
+    return d.children ? Math.max.apply(Math, d.children.map(maxY)) : d.y + d.dy;
 }
 
 /* Use a formula for contrasting colour
    http://www.w3.org/WAI/ER/WD-AERT/#color-contrast
 */
 function brightness(rgb) {
-  return rgb.r * .299 + rgb.g * .587 + rgb.b * .114;
-}
+    return rgb.r * .299 + rgb.g * .587 + rgb.b * .114;
+}
\ No newline at end of file
diff --git a/main/inc/lib/skill.lib.php b/main/inc/lib/skill.lib.php
index b99bbda788..0c9c0ba67f 100644
--- a/main/inc/lib/skill.lib.php
+++ b/main/inc/lib/skill.lib.php
@@ -593,6 +593,7 @@ class Skill extends Model {
         unset($skills);
         return $skills_tree;
     }
+    
     /**
      * Get skills tree as a simplified JSON structure
      * 
@@ -600,8 +601,10 @@ class Skill extends Model {
     public function get_skills_tree_json($user_id = null, $return_flat_array = false) {
         $tree = $this->get_skills_tree($user_id, $return_flat_array);
         $simple_tree = array();
-        foreach ($tree['children'] as $element) {
-            $simple_tree[] = array('name' => $element['name'], 'children' => $this->get_skill_json($element['children']));
+        if (!empty($tree['children'])) {
+            foreach ($tree['children'] as $element) {
+                $simple_tree[] = array('name' => $element['name'], 'children' => $this->get_skill_json($element['children']));
+            }
         }
         //$s = array('\/');
         //return str_replace($s,'/',json_encode($simple_tree[0]['children']));
diff --git a/main/template/default/skill/skill_wheel.tpl b/main/template/default/skill/skill_wheel.tpl
index 19a5e0278f..13e380f54d 100644
--- a/main/template/default/skill/skill_wheel.tpl
+++ b/main/template/default/skill/skill_wheel.tpl
@@ -1,15 +1,15 @@
 <div id="menu" class="well" style="top:20px; left:20px; width:380px; z-index: 9000; opacity: 0.9;">
-    <h3>{{'Skills'|get_lang}}</h3>
+    <h3>{{ 'Skills'|get_lang }}</h3>
     <div class="btn-group">
-        <a style="z-index: 1000" class="btn" id="add_item_link" href="#">{{'AddSkill'|get_lang}}</a>
-        <a style="z-index: 1000" class="btn" id="return_to_root" href="#">{{'Root'|get_lang}}</a>
-        <a style="z-index: 1000" class="btn" id="return_to_admin" href="{{_p.web_main}}admin">{{'BackToAdmin'|get_lang}}</a>
-        
+        <a style="z-index: 1000" class="btn" id="add_item_link" href="#">{{ 'AddSkill'|get_lang }}</a>
+        <a style="z-index: 1000" class="btn" id="return_to_root" href="#">{{ 'Root'|get_lang }}</a>
+        <a style="z-index: 1000" class="btn" id="return_to_admin" href="{{ _p.web_main }}admin">{{ 'BackToAdmin'|get_lang }}</a>        
     </div>
 </div>
            
-<div id="vis"><img src=""></div>
-{{ html }}
+<div id="vis">
+    <img src="">
+</div>
 
 <!--div id="dialog-form" style="display:none; z-index:9001;">    
     <p class="validateTips"></p>