Untitled

JavaScript addEvent function
function addEvent(elem, event, func ) {
   if (typeof (window.event) != 'undefined')
        elem.attachEvent('on' + event, func);
   else
       elem.addEventListener(event, func, false);
}

<a href="#" id="link">link</a>

addEvent(window, 'load', function (){
   // add another event
   var link= document.getElementById('link');
   addEvent(link, 'click', function () {alert('Hi'); });
});

function attachEvent(element, event, callbackFunction) {
    if (element.addEventListener) {
        element.addEventListener(event, callbackFunction, false);
    } else if (element.attachEvent) {
        element.attachEvent('on' + event, callbackFunction);
    }
};

typeof (window.event) != 'undefined'

!!window.attachEvent

function addEvent(elem, event, func ) {
    if (!!window.attachEvent){

        elem.attachEvent('on' + event, func);
    }
    else{
       elem.addEventListener(event, func, false);
    }
}

function addEvent(elem,event,func)
{
    var evn = "on"+event;
    elem[evn] = func;
}
var obj = document.getElementById("link");
addEvent(obj,"click",function(){alert('hi');});