// Start of documentspub.js
    
    var prm = Sys.WebForms.PageRequestManager.getInstance();
    prm.add_initializeRequest(InitializeRequest);
      
    // Asynchronous postback event handler
    function InitializeRequest(sender, args){
        if (sender._postBackSettings.sourceElement.id == "ctl00_ContentPlaceHolder1_lnkDocDownload"){
            // Get reference to hidden IFrame
            var iframe = document.getElementById('ctl00_ContentPlaceHolder2_ifrFileDownload');
            // Get the generated url
            var source = $get("ctl00_ContentPlaceHolder1_txtFileSource").value;
            // Setting the src of the IFrame triggers page loading 
            iframe.src = source;
        }
        
    }
    
// End of documentspub.js