RequiredFieldValidator on dropdownlist

How can I force web users to explicitly select an option on the dropdowlist?  By default, dropdownlist selects the one appears.  It makes RequiredFieldValidator on dropdownlist useless.  

Do I miss something about the Validator?  If I can not make the validator to work,  I can do dynimic validation on the server side but I don't know the best practice to do client validation.

Please help.

Biang
Jinghui LiAsked:
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praneethaCommented:
here is the solution using required field validator....

InitialValue="0" - in required field validator - is the key thing..let "0" be the value of first element which is by default selected in dropdownlist...



<asp:RequiredFieldValidator id="RequiredFieldValidator1" style="Z-INDEX: 107; LEFT: 208px; POSITION: absolute; TOP: 224px"
                        runat="server" ErrorMessage="RequiredFieldValidator" ControlToValidate="DropDownList1" InitialValue="0"></asp:RequiredFieldValidator>

                  <asp:DropDownList id="DropDownList1" style="Z-INDEX: 106; LEFT: 208px; POSITION: absolute; TOP: 184px"
                        runat="server" Width="96px">
                        <asp:ListItem Value="0">Select</asp:ListItem>
                        <asp:ListItem Value="1">1</asp:ListItem>
                        <asp:ListItem Value="2">2</asp:ListItem>
                  </asp:DropDownList>
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praneethaCommented:
i guess since something is allready selected...it won't fire the required field validator...

you can instead write javascript to check if the dropdownlist index chnaged
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Jinghui LiAuthor Commented:
I am inspired by this article in google.  Use CompareValidator with NotEqual to the default selected value.

http://www.google.com/groups?q=requiredfieldvalidator,+dropdownlist&hl=en&lr=&ie=UTF-8&selm=%23pCp6gYgBHA.1640%40tkmsftngp07&rnum=10
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praneethaCommented:
yep that's a good idea..thank u for sharing
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Jinghui LiAuthor Commented:
I believe ASP.NET should have designed RequiredFieldValidator to handle this normal scenario.  Thank you  praneetha for finding it out.  I think th trick here is the setting of InitialValue.  Well done!
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praneethaCommented:
thank u and you are welcome..i learnt something new too...

have a good weekend
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