title: Trigger UpdatePanel on mouse over (as tooltip)
body: <p>I need to display aditional information, like a tooltip, but it's a lot of info (about 500 - 600 characters) on the items in a <code>RadioButtonList</code>. </p>
  
  <p>I now trigger the update on a <code>PanelUpdate</code> when the user selects an item in the <code>RadioButtonList</code>, using <strong>OnSelectedIndexChanged</strong> and <strong>AutoPostBack</strong>. What I would like to do, is trigger this on <strong>onMouseHover</strong> (ie. user holds the mouse a second or two over the item) rather than mouse click but I cannot find a way to do this.</p>