onload event - Add function on windows.load works only on the same javascript -

why script :

function addloadevent(func) {     var existing = window.onload;       window.onload = function () {         if (typeof (existing) == "function") {             existing();         }         func();     };  } 

works js file "func()" resides? how can abstract script?

you try change tag <script></script> @ <script type="text/javascript"></script>.