Question

when i set range of my text box i get error when i remove or comment it page runs kindly see my code and tell me error in it.

<asp:TextBox ID="TxtName" runat="server" ValidationGroup="Adduser" MaxLength="32"
                        Width="200px"></asp:TextBox>
                </td>
                <td>
                    <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ValidationGroup="Adduser"
                        ErrorMessage="Provide user name" ControlToValidate="TxtName" Display="Dynamic">*</asp:RequiredFieldValidator>
                        <%--<asp:RegularExpressionValidator ID="RegularExpressionValidator2" runat="server" ValidationGroup="Adduser" ControlToValidate="TxtName" ErrorMessage="User ID Must be at least 8 Alpha Numeric Characters." ValidationExpression="^[a-zA-Z0-9]{8,}$">*</asp:RegularExpressionValidator>--%>
                    <asp:RangeValidator ID="RangeValidator2" runat="server" ErrorMessage="The ID Must Be 8 Characters." MaximumValue="32" MinimumValue="8" ControlToValidate="TxtName" Type="String"></asp:RangeValidator>
                </td>

Answer 1

You shouldn’t use RangeValidator for String type instead use RegularExpressionValidator

Try this,

<asp:TextBox ID="TxtName" 
             runat="server" 
             ValidationGroup="Adduser" 
             MaxLength="32"
             Width="200px"></asp:TextBox>

<asp:RegularExpressionValidator 
             ID="RegularExpressionValidator2" 
             runat="server" 
             ValidationGroup="Adduser" 
             ControlToValidate="TxtName" 
             ErrorMessage="User ID Must be at least 8 Alpha Numeric Characters."
             ValidationExpression="[a-zA-Z0-9]{8}">*</asp:RegularExpressionValidator>