0 problem about AutoCompleteExtender

Hi:

I meet a problem when display some data including "0"; such like string[] test={"000678", "00123","000345"}

And in this example, the autocomplet listitem can not show 000678, instead, it shows 678;

My setting about AutoCompleteExtender is following:

<asp:AutoCompleteExtender ID="AutoCompleteExtender1" runat="server" TargetControlID="txb1" MinimumPrefixLength="1"
                   ServicePath="~/test.asmx" ServiceMethod="GetNo" CompletionInterval="200" ></asp:AutoCompleteExtender>

If there any problem about that, or any setting I need to define, thanks a lot.