addEventListener与attachEvent

addEventListener与attachEvent的用法

HTML

<div id='aaa'>
    <p id='cccc' style="background:#c00;">点击</p>
</div>
<div id="bbb" style=" background:blue;">1</div>

JavaScript

function addEvent(elm, evType, fn, useCapture) {
    if (elm.addEventListener) {
        elm.addEventListener(evType, fn, useCapture); //DOM2.0
        return true;
    } else if (elm.attachEvent) {
        var r = elm.attachEvent('on' + evType, fn); //IE5+
        return r+222;
    } else {
        elm['on' + evType] = fn; //DOM 0
    }
}

function valert(){
    alert('22222sss2');
}


var ccc = document.getElementById('cccc');
addEvent(ccc,'click',valert,false);