ASP Validator: Validate lowercase and uppercase letter only

Question

<asp:Label ID="lblDriving" runat="server" CssClass="lblDriving">Driving (y/n)</asp:Label>
<asp:TextBox ID="tbDriving" runat="server" CssClass="tbDriving"></asp:TextBox> 
<asp:RequiredFieldValidator ID="rfvDriving" runat="server" CssClass="errorAsterik" ErrorMessage="Please enter y or n in lowercase only" ControlToValidate="tbDriving">*</asp:RequiredFieldValidator>
<asp:RangeValidator ID="rvDriving" runat="server" CssClass="errorAsterik" ErrorMessage="Please enter n or y in lower case" ControlToValidate="tbDriving" MinimumValue="n" MaximumValue="y">*</asp:RangeValidator>

How do i validate it so the user can enter a lowercase y/n or uppercase Y/N using the ASP.NET Validators?

Answer 1

You could use a RegularExpressionValidator:

<asp:RegularExpressionValidator ID="rvDriving" runat="server" 
   CssClass="errorAsterik" ErrorMessage="Please enter n or y" 
   ControlToValidate="tbDriving" 
   ValidationExpression="[yYnN]">*</asp:RegularExpressionValidator>