As the name implies, the RequiredFieldValidator is
used to make sure that the user enter a value for a specific field in the form.
A RequiredFieldValidator can be associated with a
control which cannot be empty while submitting the form.
The below code snipet adds a TextBox to an Asp.net
form and associates an Asp.Net RequiredFieldValidator to the text box to
make sure that the Name is entered before submitting the form.