Multiselect select element - capturing current option set before adding / removing new items

Hello and thank you for reading.

I have an aspx form hosted in SharePoint 2010 that has some multiple select elements within a form. There are buttons to add and remove options from these select elements.

My problem is that I need to run a query based on the options within these multi select elements each time new options are added / removed from them. SharePoint is executing some server side code I don't have access to but here's my underlying problem.

If I hook into the buttons' onclick event, when my function is called the options have already been added to or removed from the select element. I need to capture the current option set of these elements, before the onclick function executes.

Is there another event I can tie into? Something like onbeforeclick on the buttons or optionsChanged on the multi select element? It doesn't look like any event will sat开发者_如何学Cisfy what I need to do here, but I'm hoping someone has faced a similar issue before.

Thanks,

Zachary Carter

The only solution I could come up with is to capture the present set of options each time an option is added or removed.

This solution is going to involve alot of array manipulation however, and if I can avoid that and simply tie into an event, before the onclick event of the button is called, that would be my ideal solution.

This might not be a great answer to your question, and if not, I apologize. However, I just ran into a very similar problem, albeit using Visual Basic. The solution wasn't elegant in my eyes, but I used VB's MouseUp event, which fires when the mouse button is released. On release (i.e., at the end of the previous action), I save all the information in the elements into an array, and then on the next click, before anything else happens, I can check against that array.

Edit: Gah, looks like you posted essentially that solution while I was typing. Sorry I didn't notice.