This can be done using the following script tag:
<script>
function pageLoad()
{
$find('TextBox1_DropDownExtender')._dropWrapperHoverBehavior_onhover();
$find('TextBox1_DropDownExtender').unhover = VisibleMe;
}
function VisibleMe()
{
$find('TextBox1_DropDownExtender')._dropWrapperHoverBehavior_onhover();
}
</script>
I found this and some other tips in this net curry example .
This works, but I would also like to write a new control based on a drop down extender providing a property to set what you want to turn on or off.
AJAX , .