Numbers only
<asp:CompareValidator runat="server" Operator="DataTypeCheck" Type="Integer"
ControlToValidate="ValueTextBox" ErrorMessage="Value must be a whole number" />⚠ However, this allow only integer of 10 digits
The following is for numbers only
<asp:CompareValidator runat="server" Operator="DataTypeCheck" Type="Integer" ControlToValidate="FileNumberTextBox" ValidationGroup="company" >ERROR, # only</asp:CompareValidator>