I really need halp on this one.

I am trying to display a message box for mandatory fields only.  However the message box still appears for the optional fields such as phone, comments and email when I click Add Student.  Can any one give me any advice on excluding the optinal fields.  I have entered the piece of code that am working on for this for this section.

private void btnAddNewStud_Click(object sender, System.EventArgs e)
  {
   foreach(System.Windows.Forms.Control aControl in this.Controls)
   {
    if(aControl is System.Windows.Forms.TextBox & aControl.Text
     == "") 
    {
     MessageBox.Show("Please ensure that the First Name, Last Name, Address and Course details are entered");
     aControl.Focus();
     return;
    
     if(aControl is System.Windows.Forms.TextBox & aControl.Name == "txtEmail")
     {
      return;      
     }
     
    }
   }

END: I have tried using a 2nd 'If' statement to test when the email text box is reached and to return straight away but this doesnt seem to work.

Any help would be great