function switch_edit_preview()
{
    var post_edit = document.getElementById("post_edit");
    var post_preview = document.getElementById("post_preview");

    if(post_edit.style.display == "none")
    {
        post_edit.style.display = "block";
        post_preview.style.display = "none";
    }
    else
    {
        send_request('POST', 'preview.php', 'submit=ajax&action=preview&text=' +  + '&is_comment=0',
        function(request)
        {
            post_preview.innerHTML = request.responseText;
        });
        post_preview.innerHTML = '<img src="tpl/loading.gif" width=32 height=32 border=0>';

        post_edit.style.display = "none";
        post_preview.style.display = "block";
    }
}