Relatively simple javascript code _ javascript skills for loading JS files Asynchronously

Implement function code for loading JS files asynchronously. The Code is as follows:

Script
Function getJsFile (url, callBack ){
Var XH = window. XMLHttpRequest? New XMLHttpRequest: new ActiveXObject ('msxml2. xmlhttp ');
XH. open ('get', url, true );
XH. onreadystatechange = function (){
If (XH. readyState = 4 & XH. status = 200 ){
If(window.exe cScript) window.exe cScript (XH. responseText );
Else eval. call (window, XH. responseText );
Eval (callBack )();
}
}
XH. send ('');
}
Script

The Code is as follows:

// Test
Script
Function cb (){
Alert (1 );
Abc (); // This is in js9.js
}
GetJsFile ('HTTP: // www.jb51.net/images/test.js,'cb ');
Script