function get_video_info(root_dir){
    //alert(document.input.video_url.value);
    //alert("test");
    xmlHttp = ajaxFunction();
    if(xmlHttp){
        xmlHttp.open("POST", root_dir + "ajx/youtube.php", true);
	
		xmlHttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
        xmlHttp.send("video_url="+document.input.video_url.value+"&entity_id="+document.input.entity_id.value+"&entity_type="+document.input.entity_type.value+"&post_action="+document.input.video_post_action.value);
		xmlHttp.onreadystatechange = function() {
            if (xmlHttp.readyState == 4) {
				if (xmlHttp.status == 200) {
						document.getElementById("video_inf").innerHTML=xmlHttp.responseText;
				}
				else {
				   alert("some error");
				}
			}
		}	
    }
	
    return false;
}