In this tutorial you'll find out how to validate a TextBox and RadioButtonList control on a webform using RequiredFieldValidator, which will show a warning and stop the submission of the form if a required field has no value.
Date Validation in ASP.NET ASP.NET / General Development
In this tutorial, we will try to validate some data coming from a form input. While using this sampel code will check the date is true and in correct format. We will compare the date within a culture date format.
Sending Mass E-Mails using ASP.NET ASP.NET / Emailing
How to validate user input i.e. what if user enters nothing or enters invalid information in the HTML form input boxes and how to send mass emails to a list of email addresses without the user knowing that the same email has been sent to other users as well.