load script in html
var oBody = document.getElementsByTagName('body').item(0),
oHead = document.getElementsByTagName('head').item(0);
var zeptoScriptTag= document.createElement("script");
zeptoScriptTag.type = "text/javascript";
zeptoScriptTag.src="zepto-core.min.js";
oBody.appendChild(zeptoScriptTag);
zeptoScriptTag.onload = function (){
var appScriptTag= document.createElement("script");
appScriptTag.type = "text/javascript";
appScriptTag.src="app.js";
oBody.appendChild(appScriptTag);
};