var on = function(node, eventType, param, callback) {
            node = typeof node === 'string' ? document.getElementById(node) : node;
            if(node.addEventListener){
                node.addEventListener(eventType, function(event){
                    event.data = param;
                    callback.call(node, event);
                }, false);
            }else{
                node.attachEvent('on' + eventType, function(){
                    event.data = param;
                    callback.call(node, event);
                });
            }
        }

------解决方案--------------------
on : function(node, eventType, param, scope, callback) {
node = typeof node === 'string' ? document.getElementById(node) : node;

function innerCallback()
{
var scope = scope || window;
var param = param;  
callback.apply(scope,param);
}

if (document.all)
node.attachEvent('on' + eventType, innerCallback);
else
node.addEventListener(eventType, function(event){
innerCallback(event);
}, false);
}