Display-Hide-Div with Iframe

Display-Hide-Div with Iframe.

//ctrl is ouetrmost Div Id
// wysiwygctl00_PlaceHolderMain_txtDescription is the Iframe Id
function DisplayNewPost(ctrl)
{
            var
PreState=document.getElementById(ctrl).style.display;
    if(PreState!="none")
            {
                document.getElementById(ctrl).style.display="none";
            }
            else
            {

       document.getElementById(ctrl).style.display="block";

       var content = document.getElementById('ctl00_PlaceHolderMain_txtDescription').value;               

       var doc = document.getElementById("wysiwygctl00_PlaceHolderMain_txtDescription").contentWindow.document;         // Write the textarea's content into the iframe
       doc.open();
       doc.write(content);
       doc.close();              
       // Make the iframe editable in both Mozilla and IE
       doc.body.contentEditable = true;
       doc.designMode = "on";

            }
}