clear option in SELECT drop down menu

[liunx]

I have created 3 drop down menu where each has 10 options for selection. How can i clear the 1st selection(e.g. HUH station) if user tried to do the 2nd selection (LionRock) from the 2nd drop down menu? <br />
here is the example <br />
<select name="menu3" onChange="MM_jumpMenu('parent.context',this,0)"><br />
<option value="GI-Context.htm" selected>--- Please Select <br />
---</option><br />
<option value="HUH Station.htm">Hung Hom Station</option><br />
<option value="Whampoa.htm">Whampoa</option><br />
</select><br />
</p><br />
<font face="Arial, Helvetica"><font size="2"><nobr><b>Lion Rock:</b></font></font> <br />
<select name="LRMenu" onChange="MM_jumpMenu('parent.context',this,0)" size="1"><br />
<option value="GI-Context.htm" selected>--- Please Select <br />
---</option><br />
<option value="LionRock.htm">Lion Rock</option><br />
<option value="LionRock.htm">Lion Rock</option><br />
</select><br />
<br />
<br />
<br />
thks<br />
Kara<!--content-->To "clear" a select object you must set the selectedIndex to -1.<!--content-->I tried to inluded Selectedindex.-1, e.g., <select name="menu1" onchange="MM_jumpmenu('parent.context', this, 0)" selectedindex.01><br />
<br />
but it is not working. would you please give me a example to show how to do it?<br />
<br />
thks<!--content--><select name="menu1" onchange="MM_jumpmenu('parent.context', this, 0);this.selectedIndex=-1"><br />
You may want to put it in the function rather than the select tag. There may be some timing issues.<!--content-->Gil, thank you for your help. The problem is solved now.<br />
<br />
cheers<!--content-->