private void button_Accept_Click(object sender, EventArgs e)
 {
     if (SQLFunctions.checkExistsUsers(Convert.ToInt32(listView1.SelectedItems[0].SubItems[0].Text)) == true)
     {
         SQLFunctions.deleteUser(Convert.ToInt32(listView1.SelectedItems[0].SubItems[0].Text));
         MessageBox.Show("User with ID: " + listView1.SelectedItems[0].SubItems[0].Text + " was deleted!");
         this.Hide();
         FormMenuAdmin adminForm = new FormMenuAdmin();
         adminForm.Show();
     }
     else
     {
         MessageBox.Show("User ID could not be located in the database");
     }
 }