Check value Numeric is not(validation control server side)

asp:TextBox ID="TextBox1" runat="server" CausesValidation="True">/asp:TextBox>
asp:RequiredFieldValidator
ID="RequiredFieldValidator1" runat="server"
ErrorMessage="Pless Enter textbox1 value" ControlToValidate="TextBox1">*/asp:RequiredFieldValidator>
asp:CompareValidator ID="CompareValidator1" runat="server" ControlToValidate="textbox1"
ErrorMessage="Enter numeric value" Operator="DataTypeCheck" SetFocusOnError="True"
Type="Integer">/asp:CompareValidator>

asp:ValidationSummary ID="ValidationSummary1" runat="server" />