error message in login page

[rocky811]

i have a login page wid login check up loop as if (userType.Equals("Administrator")) { Response.Redirect("successPage.aspx"); } else if (!userType.Equals("Administrator")) { errMessage.Text = " Login Incorrect!! " ; } login works well..but if i click wrong details.. it displays nothing.. i want to display text above... how to do this ??

[Prateek G]

To Display Message Box - Response.Write(" alert('Loging Incorrect');");