Enforcing Maximum character length Validation (Maximum of 5 letters).

Hear,we will also use Asp.net RegularExpressionValidator control to achieve this task:-

Refer below code:-

<asp:TextBox Id = "txt_employee_code" runat = "server"></asp:TextBox>

<asp:RegularExpressionValidator Display = "Dynamic" 
ControlToValidate = "txt_employee_code" Id = "reg_ex_employee_code" 
ValidationExpression = "^[\s\S]{0,5}$" runat = "server" 
ErrorMessage = "Maximum of 5 letters allowed">
</asp:RegularExpressionValidator>

It will allow only 5 letters after that it will give error message as Maximum of 5 letters allowed.