// Remove Machine
 public bool RemoveMachine(string ID)
 {
     if (ID != "" & ID != null)
     {
         List <Machine> machine = database.SelectMachine(ID);
         if (machine.Count == 1)
         {
             database.Remove(machine[0]);
             return(true);
         }
         else
         {
             return(false);
         }
     }
     else
     {
         return(false);
     }
 }