private void btn_CreateClass_Click(object sender, EventArgs e)
 {
     if (txt_Class.Text != "")
     {
         var Class = new SchoolClass(txt_Class.Text);
         if (Class.CreateClass() == true)
         {
             MessageBox.Show("Class Created Sucessfully");
             Directory.CreateDirectory("Quiz/" + txt_Class.Text);
             txt_Class.Text = "";
         }
     }
     else
     {
         MessageBox.Show("Empty! Plz enter class name");
     }
 }