Getting the index in a function in a each loop?

[Matt Thomson]

Hi does anyone know how I would do this:

html:

<div id="img_holder">
   <img src="img1.gif" />
   <img src="img2.gif" />
   <img src="img3.gif" />
</div>

javascript:

this.imageArray = $('img_holder').getElements('img');

this.imageArray.each(function(el,index)
{
    el.addEvent('click', function()
    {
        alert(index + 1);
        //if image 1 is clicked I want it to alert "1"
       //if image 2 is clicked I want it to alert "2"
       //presently index is undefined
     });
});

Thanks,

Matt.