// Checks usrname for incorrect data
public void StudentFormSnameErroneusdate()
{
//create instance to test
StudentForm stForm = new StudentForm(ref mainform, true);
//define a test input and output value
bool expectedResult = false;
stForm.SetSnameAdded("Johnson");
//run the method under test
bool actualResult = stForm.ValidateFields();
//checks results
Assert.AreEqual(expectedResult, actualResult);
}