I am experiencing this problem for few hours now and really not sure how to solve this. However its work fine in IE but it is not working in mozilla. Here is my code:

   <!-- Skin CSS file -->
    <link rel="stylesheet" type="text/css" href="http://yui.yahooapis.com/2.7.0/build/assets/skins/sam/skin.css">
    <!-- Utility Dependencies -->
    <script type="text/javascript" src="http://yui.yahooapis.com/2.7.0/build/yahoo-dom-event/yahoo-dom-event.js"></script> 
    <script type="text/javascript" src="http://yui.yahooapis.com/2.7.0/build/element/element-min.js"></script> 
    <!-- Needed for Menus, Buttons and Overlays used in the Toolbar -->
    <script src="http://yui.yahooapis.com/2.7.0/build/container/container_core-min.js"></script>
    <script src="http://yui.yahooapis.com/2.7.0/build/menu/menu-min.js"></script>
    <script src="http://yui.yahooapis.com/2.7.0/build/button/button-min.js"></script>
    <!-- Source file for Rich Text Editor-->
    <script src="http://yui.yahooapis.com/2.7.0/build/editor/editor-min.js"></script>
    <script>
           var myEditor = new YAHOO.widget.Editor('msgpost', {
        height: '100px',
        width: '522px',
        dompath: true, //Turns on the bar at the bottom
        animate: true //Animates the opening, closing and moving of Editor windows
    });
    myEditor.render(); 
    //Inside an event handler after the Editor is rendered
    YAHOO.util.Event.on('save', 'click', function() {
        //Put the HTML back into the text area
        myEditor.saveHTML();

        //The var html will now have the contents of the textarea
        var html = myEditor.get('msgpost').value;
    });
    YAHOO.util.Event.on('edit', 'click', function() {
        //Put the HTML back into the text area
        myEditor.saveHTML();

        //The var html will now have the contents of the textarea
        var html = myEditor.get('msgpost').value;
    });



        </script> 

    <form id="form2" name="form2" method="post" action="processgreeting.php">

     <div class="span-22 gtype"  >
     <div class="span-5"><label>Message:</label></div>
     <div class="span-17 last"><textarea name="msgpost" id="msgpost" cols="50" rows="40"> </textarea> <br>  
     </div>

    <input type="submit" name="save" value="Post Greeting"  id="postgreeting"/>

    </form>

processgreeting.php
if(isset($_POST['save']))
{

 $body = trim($_POST['msgpost']);

  $valid = 1;
  $publish_date = strtotime($publish); 
   if ($publish >= $today)
    {
    $valid = 0;
    $insert_greeting = "INSERT INTO greeting (type,decs,name,message,date,user,publish) VALUES ('$type','$desc','$name','$body','$today',$user,'$publish')";
    $register_greeting = mysql_query($insert_greeting)or die(mysql_error());
    $lastnum = mysql_insert_id(); 
    $_SESSION["greetingno"] = $lastnum; 
    if($valid == 0)
    {
    echo '<strong>Greeting Type: </strong>'.$type.'<br><strong>Description: </strong>'.$desc.'<br><strong>Name: </strong>'.$name.'<br><strong>Message: </strong>'.$body.'<strong><br>Publish Date: </strong>'.$publish;
    }

    //echo $valid;
    }
   else{ //echo "<span style='color:#FF0000'>Publish date is invalid</span>" ;
   echo $valid;
        }  //} 

}

Herkes iam ne yanlış yaptığını bana yardımcı olabilir misiniz ..

Şimdiden teşekkürler.