private void assignments_click(object sender, RoutedEventArgs e) //opens the window to display assignments
{
string date = "";
StudentAssignments student = new StudentAssignments(date);
student.ShowDialog();
viewCompletedAssignments.Items.Clear();
open_completed_file();
viewPastDue.Items.Clear();
MyAssignments.Clear();
due_today.Items.Clear();
background.ClearDates();
open_assignments_file();
}
