var prm=Sys.WebForms.PageRequestManager.getInstance();prm.add_initializeRequest(InitializeRequest);function InitializeRequest(sender,args){if(sender._postBackSettings.sourceElement.id=="ctl00_ContentPlaceHolder1_lnkDocDownload"){var iframe=document.getElementById('ctl00_ContentPlaceHolder2_ifrFileDownload');var source=$get("ctl00_ContentPlaceHolder1_txtFileSource").value;iframe.src=source;}}