var asset_iframe_url = '';
function load_url_asset(url) {
    
	var iframe = document.getElementById('urlasset');
	if(url == 'null' || url == null || url == '' || url == asset_iframe_url) {
		url = 'about:blank';
		iframe.style.display = "none";
	    iframe.style.visibility = "hidden";
	}
	else {
		iframe.style.display = "block";
	    iframe.style.visibility = "visible";
	}
	asset_iframe_url = url;
	iframe.src = url;
}