https://www.typist.jp/js/attachevent.js

1//*** This code is copyright 2003 by Gavin Kistner, [email protected]
2//*** It is covered under the license viewable at http://phrogz.net/JS/_ReuseLicense.txt
3//*** Reuse or modification is free provided you abide by the terms of that license.
4//*** (Including the first two lines above in your source code satisfies the conditions.)
5
6
7//***Cross browser attach event function. For 'evt' pass a string value with the leading "on" omitted
8//***e.g. AttachEvent(window,'load',MyFunctionNameWithoutParenthesis,false);
9
10function AttachEvent(obj,evt,fnc,useCapture){
11	if (!useCapture) useCapture=false;
12	if (obj.addEventListener){
13		obj.addEventListener(evt,fnc,useCapture);
14		return true;
15	} else if (obj.attachEvent) return obj.attachEvent("on"+evt,fnc);
16	else{
17		MyAttachEvent(obj,evt,fnc);
18		obj['on'+evt]=function(){ MyFireEvent(obj,evt) };
19	}
20} 
21
22//The following are for browsers like NS4 or IE5Mac which don't support either
23//attachEvent or addEventListener
24function MyAttachEvent(obj,evt,fnc){
25	if (!obj.myEvents) obj.myEvents={};
26	if (!obj.myEvents[evt]) obj.myEvents[evt]=[];
27	var evts = obj.myEvents[evt];
28	evts[evts.length]=fnc;
29}
30function MyFireEvent(obj,evt){
31	if (!obj || !obj.myEvents || !obj.myEvents[evt]) return;
32	var evts = obj.myEvents[evt];
33	for (var i=0,len=evts.length;i<len;i++) evts[i]();
34}