//方法一
var actualCode = "setTimeout('__doPostBack(\\'ddlDptCode\\',\\'\\')', 0)";
var script = document.createElement('script');
script.textContent = actualCode;
(document.head||document.documentElement).appendChild(script);
script.remove();
//方法二
(function() {
var a = 1;
var s = document.createElement('script');
s.textContent = "setTimeout('__doPostBack(\\'ddlDptCode\\',\\'\\')', 0)";
document.documentElement.append(s);
})();