if(typeof jQuery=='undefined') {
    var headTag = document.getElementsByTagName("head")[0];
    var jqTag = document.createElement('script');
    jqTag.type = 'text/javascript';
    jqTag.src = 'https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js';
    jqTag.onload = setFileManager();
    headTag.appendChild(jqTag);
} else {
     setErrorMsg();
}

function setErrorMsg(){
	alert("URL is not allowed");
}