title: How to change label text on mouseover in asp.net
body: <p>In asp.net, when the user mouses over a button, I'd like to change the text of a label to explain what the button does. </p>
  
  <p>Then when they mouse-out of the button, the label should go back to its default text.</p>
  
  <p>What is the best way to achieve this?  Are there ASP.net controls for this?  Or should I just code custom javascript?</p>