Ok, I’ve forgotten this more times than I care to remember, and each time, I have to re-Google it.  I hereby commit it to digital memory:

If you have a DropDownList control like so:

<asp:DropDownList ID="mycontrol" runat="server"></asp:DropDownList>

and you want to get it’s selected value in JavaScript, do it like so:

var control = $get('<%= this.mycontrol.ClientID %>');
var selectedvalue = control.options[control.selectedIndex].value;

And there ya have it.  I hereby have forgotten it already… :D

Rob