Question

I have an asp.net page with several list boxes.

I would like to include some javascript on the page that allows a user to drag individual list elements from one box to another.

On a normal web page, the script to do this is reasonably simple, however, with the element IDs generated by ASP.NET, I don’t know what identifiers to have my script look up?

Any thoughts on how to do something like this?

Answer 1

Check out the ClientId property of the Control class.

Note: The ASP.NET ListBox control inherits from Control.

Update

In reponse to the comments below, I can think of two ways to access the individual li elements of an unordered / ordered list generated by the ListBox control.

• Create a custom Control that inherits from
  the ListBox control and renders out an
  id attribute for each li element.
• Use the getElementsByTagName method
  in JavaScript. MSDN even has an
  example that uses the
  getElementsByTagName method to get
  the children of an unordered list and
  displays an alert indicating the
  number of children and the value of
  the first child element. If the MSDN documentation isn’t your thing, you can check out the MDC documentation as well.