disable the submit button on click (with 2 validators)

hi guys..
i wanna disable my submit button on click.. it's working fine if i have removed [validation group]. please advise. tq HTML
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox> <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="TextBox1" Display="Dynamic">Required</asp:RequiredFieldValidator> <br /> <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox> <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="TextBox2" Display="Dynamic" ValidationGroup="submit">Required</asp:RequiredFieldValidator> <br /> <asp:button id="btnOne" tabIndex="0" Runat="server" Text="Submit" ...