How do I clear the dropdownlist values on button click event using jQuery?
A shorter alternative to the first solution given by Russ Cam would be:
This assumes you want to retain the list, but make it so that no option is selected.
If you wish to select a particular default value, just pass that value instead of an empty string.
or to do it by the index of the option, you could do:
$('#mySelect option:eq(0)').attr('selected','selected'); // Select first option