public bool checkStaffField(string input)
{
bool isExist= false;
Thread checkStaff = new Thread(()=> {
switch (this.Field)
{
case "username": isExist = StaffModel.checkUniqueStaffUsername(input); break;
case "email": isExist = StaffModel.checkUniqueStaffEmail(input); break;
default: isExist = false; break;
}
});
checkStaff.SetApartmentState(ApartmentState.STA);
checkStaff.Start();
checkStaff.Join();
return isExist;
}