addEvent

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;     
    }     
    else {     
        elm[\'on\' + evType] = fn;//DOM 0     
    }     
}