diff --git a/main/inc/lib/message.lib.php b/main/inc/lib/message.lib.php
index 57e5613930..d2b1b2abf2 100755
--- a/main/inc/lib/message.lib.php
+++ b/main/inc/lib/message.lib.php
@@ -213,7 +213,10 @@ class MessageManager
 			}
 		}
 		
-		if ($total_filesize > intval(api_get_setting('message_max_upload_filesize'))) {			
+		// validating fields
+		if (empty($subject)) {
+			return get_lang('YouShouldWriteASubject');
+		} else if ($total_filesize > intval(api_get_setting('message_max_upload_filesize'))) {			
 			return sprintf(get_lang("FilesSizeExceedsX"),format_file_size(api_get_setting('message_max_upload_filesize')));
 		}
 		
diff --git a/main/messages/send_message.php b/main/messages/send_message.php
index bcbe075d79..f7f81429bd 100755
--- a/main/messages/send_message.php
+++ b/main/messages/send_message.php
@@ -49,15 +49,14 @@ if ($panel_id == 2 || $panel_id == 4 )  {
 	<dd><a href="javascript:void(0)" onclick="change_panel('1','<?php echo $user_id; ?>')"><?php echo api_xml_http_response_encode(get_lang('SendMessage'));?></a></dd>
 </dl>
 <?php
-}elseif($panel_id == 5 && empty($content_message)) {
+}elseif($panel_id == 5 && empty($subject_message)) {
 ?>
 	 <div id="display_response_id" style="height:200px;">
 	 <?php echo api_xml_http_response_encode(get_lang('To')); ?> :&nbsp;&nbsp;&nbsp;&nbsp;<?php echo api_xml_http_response_encode(api_get_person_name($user_info['firstName'], $user_info['lastName'])); ?>			  		 
 	 <br />
-	 <br /><?php echo api_xml_http_response_encode(get_lang('Subject')); ?> :<br /><input id="txt_subject_id" type="text" style="width:300px;"><br/>
-	 <br /><?php echo api_xml_http_response_encode(get_lang('Message')); ?> :<br /><textarea id="txt_area_invite" rows="4" cols="40"></textarea>
-	 <?php echo api_xml_http_response_encode(get_lang('YouShouldWriteAMessage'));  ?><br />
-	 <br />
+	 <br /><span style="color:red">*</span><?php echo api_xml_http_response_encode(get_lang('Subject')); ?> :<br /><input id="txt_subject_id" type="text" style="width:300px;"><br/>
+	 <br /><?php echo api_xml_http_response_encode(get_lang('Message')); ?> :<br /><textarea id="txt_area_invite" rows="3" cols="40"></textarea>	 
+	 <?php echo Display::display_error_message(api_xml_http_response_encode(get_lang('YouShouldWriteASubject')));  ?>	 
 	 <button class="save" type="button" value="<?php echo api_xml_http_response_encode(get_lang('SendMessage')); ?>" onclick="action_database_panel('5','<?php echo $user_id;?>')">
 	 <?php echo api_xml_http_response_encode(get_lang('SendMessage')) ?></button>
 	 </div>
@@ -68,7 +67,7 @@ if ($panel_id==4 && !empty($content_message)) {
 		$subject_message=null;
 	}	
 	SocialManager::send_invitation_friend_user($user_id,$subject_message,$content_message);
-} elseif ($panel_id==5 && !empty($content_message) ) {
+} elseif ($panel_id==5 && !empty($subject_message) ) {
 	SocialManager::send_invitation_friend_user($user_id,$subject_message,$content_message);
 }
-?>
+?>
\ No newline at end of file
diff --git a/main/messages/send_message_to_userfriend.inc.php b/main/messages/send_message_to_userfriend.inc.php
index e7a5b75f5f..fc4e4f84f1 100755
--- a/main/messages/send_message_to_userfriend.inc.php
+++ b/main/messages/send_message_to_userfriend.inc.php
@@ -49,10 +49,11 @@ if ( isset($_REQUEST['user_friend']) ) {
 		   		 <div id="display_response_id" style="height:200px;">
 			  		 <?php echo api_xml_http_response_encode(get_lang('To')); ?> :&nbsp;&nbsp;&nbsp;&nbsp;<?php echo api_xml_http_response_encode(api_get_person_name($user_info['firstName'], $user_info['lastName'])); ?>			  		 
 			  		 <br />
-			 		 <br /><?php echo api_xml_http_response_encode(get_lang('Subject')); ?> :<br /><input id="txt_subject_id" type="text" style="width:300px;"><br/>
-			   		 <br /><?php echo api_xml_http_response_encode(get_lang('Message')); ?> :<br /><textarea id="txt_area_invite" rows="4" cols="40"></textarea>
+			 		 <br /><span style="color:red">*</span><?php echo api_xml_http_response_encode(get_lang('Subject')); ?> :<br /><input id="txt_subject_id" type="text" style="width:300px;"><br/>
+			   		 <br /><?php echo api_xml_http_response_encode(get_lang('Message')); ?> :<br /><textarea id="txt_area_invite" rows="3" cols="40"></textarea>			   		 
+			   		 <div><span style="color:red">*</span><?php echo get_lang('FieldRequired') ?></div>
 			   		 <br />
-			   		 <button class="save" type="button" value="<?php echo api_xml_http_response_encode(get_lang('SendMessage')); ?>" onclick="action_database_panel('5','<?php echo $userfriend_id;?>')"><?php echo api_xml_http_response_encode(get_lang('SendMessage')) ?></button>
+			   		 <button class="save" type="button" value="<?php echo api_xml_http_response_encode(get_lang('SendMessage')); ?>" onclick="action_database_panel('5','<?php echo $userfriend_id;?>')"><?php echo api_xml_http_response_encode(get_lang('SendMessage')) ?></button>			   		 
 		   		 </div>
 <?php
 			} else {
@@ -64,8 +65,7 @@ if ( isset($_REQUEST['user_friend']) ) {
  					<button class="save" type="button" value="<?php echo api_xml_http_response_encode(get_lang('SocialAddToFriends')); ?>" onclick="action_database_panel('4','<?php echo $userfriend_id;?>')" >
  					<?php echo api_xml_http_response_encode(get_lang('SendInvitation')) ?></button>
  				</div>
-<?php
-				}
+<?php			}
 			}
 ?>
 			</dl>
diff --git a/main/social/groups.php b/main/social/groups.php
index dac3ee0049..140a96f8aa 100755
--- a/main/social/groups.php
+++ b/main/social/groups.php
@@ -60,6 +60,14 @@ function add_image_form() {
 	}
 }
 
+function validate_text_empty (str,msg) {
+	var str = str.replace(/^\s*|\s*$/g,"");
+	if (str.length == 0) {		 		
+		alert(msg);
+		return true;			
+	}			
+}
+
 jQuery(document).ready(function() {
    $(".head").click(function() {   			
 		$(this).next().slideToggle("fast");
@@ -82,7 +90,6 @@ jQuery(document).ready(function() {
 		return false;
  	}).next().hide();
 });
-
 	</script>';
 
 $interbreadcrumb[]= array ('url' =>'profile.php','name' => get_lang('Social'));
@@ -108,7 +115,8 @@ if (isset($_POST['token']) && $_POST['token'] === $_SESSION['sec_token']) {
 		} else {		
 			$res = MessageManager::send_message(0, $title, $content, $_FILES, '', $group_id, $parent_id);	
 		}
-						
+		
+		// display error messages 						
 		if (is_string($res)) {			
 			Display::display_error_message($res);
 		}		
diff --git a/main/social/message_for_group_form.inc.php b/main/social/message_for_group_form.inc.php
index a3040dc27b..2dcae6b6ae 100755
--- a/main/social/message_for_group_form.inc.php
+++ b/main/social/message_for_group_form.inc.php
@@ -72,7 +72,7 @@ if (!empty($group_id) && $allowed_action) {
 		   		$user_info=api_get_user_info($userfriend_id);
 		  		echo api_xml_http_response_encode(get_lang('To')); ?> :&nbsp;&nbsp;&nbsp;&nbsp;<?php echo api_xml_http_response_encode($to_group); ?>
 		  		<br />
-		 		<br /><?php echo api_xml_http_response_encode(get_lang('Subject')); ?> :<br />
+		 		<br /><span style="color:red">*</span><?php echo api_xml_http_response_encode(get_lang('Subject')); ?> :<br />
 		 		<input id="txt_subject_id" name="title" type="text" style="width:450px;" value="<?php echo $subject ?>"><br/>
 		   		<br /><?php echo api_xml_http_response_encode(get_lang('Message')); ?> :<br />		   		
 		   		<?php
@@ -86,9 +86,10 @@ if (!empty($group_id) && $allowed_action) {
 		   		?>		   		
 		   		<br /><br /><?php echo api_xml_http_response_encode(get_lang('AttachmentFiles')); ?> :<br />
 				<span id="filepaths"><div id="filepath_1"><input type="file" name="attach_1" size="20" /></div></span>
-				<div id="link-more-attach"><a href="javascript://" onclick="return add_image_form()"><?php echo get_lang('AddOneMoreFile') ?></a>&nbsp;(<?php echo api_xml_http_response_encode(sprintf(get_lang('MaximunFileSizeX'),format_file_size(api_get_setting('message_max_upload_filesize')))) ?>)</div>		   		
+				<div id="link-more-attach"><a href="javascript://" onclick="return add_image_form()"><?php echo get_lang('AddOneMoreFile') ?></a>&nbsp;(<?php echo api_xml_http_response_encode(sprintf(get_lang('MaximunFileSizeX'),format_file_size(api_get_setting('message_max_upload_filesize')))) ?>)</div>		   				   				   		
 		   		<br />
-		   		<button class="save" type="submit" value="<?php echo api_xml_http_response_encode(get_lang('SendMessage')); ?>"><?php echo api_xml_http_response_encode(get_lang('SendMessage')) ?></button>
+		   		<button class="save" onclick="if(validate_text_empty(this.form.title.value,'<?php echo get_lang('YouShouldWriteASubject')?>')){return false;}" type="submit" value="<?php echo api_xml_http_response_encode(get_lang('SendMessage')); ?>"><?php echo api_xml_http_response_encode(get_lang('SendMessage')) ?></button>
+		   		<div><span style="color:red">*</span><?php echo get_lang('FieldRequired') ?></div>
 	<?php } ?>
 	</dl>
 </td>