public int compareTo(Object obj)
   {
            
      //makes sure the object is an instance of class Employee
      if(obj instanceof Employee)
      {
      
         //cast the object to type Employee
         Employee emp = (Employee)obj;
      
         int answer = 5;
               
         if(acctID > emp.getId())
         {
         
            answer = 1;
         
         }//end if statement
         else if(acctID < emp.getId())
         {
         
            answer = -1;
         
         }//end if statement
         else if(acctID == emp.getId())
         {
         
            answer = 0;
         
         }//end if statement
         
         return answer;
      
      }//end if statement
      
      //not an instance of class Employee, send error back to calling method
      else
      {
      
         throw new IllegalStateException("Not an object of Employee.");
      
      }//end else statement
   
   }//end compareTo method