how to display alert box in asp.net

Question

i have a registration page with a submit button.

i want to show an alert box when the \"user clicks on the submit button\" after which the \"data entered by the user

Answer 1

alerts:

Page.ClientScript.RegisterStartupScript(this.GetType(), "alert", "alerts('" + str + "');", true);

needs to be alert:

 Page.ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('" + str + "');", true);