public double nextDoublePos(String prompt)
	 {
	 	double amount = 0;
		try
		{
		 	//read first value
		 	System.out.print( prompt );	
			amount = myScan.nextDouble();
			myScan.nextLine();	//flush internal buffer
			
			//keep reading if not positive
			while( amount <= 0.0 )
			{	//invalid withdraw
				System.out.println("\tError: input must be > 0");
				
				//read next input
				System.out.print(prompt);
				amount = myScan.nextDouble();
				myScan.nextLine();
			}
		
		}
		catch(InputMismatchException ime)
		{
			System.out.println("Input mismatch. Please input a a ");
			System.exit(1);
		}
		catch(Exception e)
		{
			System.out.print("General exception. Exiting");
			System.exit(1);
		}
		return amount;
	}