Since you are able to clear the results out you should be able to get the select list to show the first value as selected by adding in the selected attribute to the first option like this:
<select name="S_EndTime" id="S_EndTime">
<option value="" selected="selected">Search Ending Times</option>
You might still have this problem though if there are any matches from the recordset that you are working with in the list. Please post back with the page in question in a zip archive and I will take a look to let you know how you can get this other recordset to not have any values initially.