GSSP-NET Question #99: Real Exam Question with Answer & Explanation

John works as a Web Developer for Bitsoft Inc. He creates an ASP.NET application, named MyApp1, by using Visual Studio .Net for a University Web site. Students will use MyApp1 to view their term end result. MyApp1 contains an ASP.NET page named, named Page1. Page1 contains a TextBox control, named txtEnrolmentNo, and two Button controls, named btnSubmit and btnCancel respectively. John wants that if a user tries to submit the page by clicking the Submit button without entering his enrolment the word "Required" appears next to txtEnrolmentNo. However, when a user clicks the Cancel button he is redirected to a new page, named PageCancel.aspx. To accomplish this he adds a RequiredFieldValidator control to the page and sets its ControlToValidate and ErrorMessage properties to txtEnrolmentNo and "Required" respectively. However, when he executes the application he finds that the validation check is also performed on clicking the Cancel button. What is the most likely cause of the issue?