[removed] Adding an onClick handler without overwriting the existing one

Question

I\'m trying to modify all links on a page so they perform some additional work when they are clicked.

A trivial approach might be something like this:

Answer 1

how about setting oldClick = links[i].onclick or an empty function. Like so

var oldOnClick = links[i].onclick || function() { return true; };

links[i].onclick = function (e)
   {
       if (!oldOnClick())
           return false;
       //
       return true;
   }

Or you could use attachEvent and addEventListener as others have recommended

function addEvent(obj, type, fn) {
        if (obj.addEventListener)
                obj.addEventListener(type, fn, false);
        else if (obj.attachEvent)
                obj.attachEvent('on' + type, function() { return fn.apply(obj, [window.event]);});
}

and use like so

addEvent(links[i], 'click', [your function here]);