while(runner){

			try{
				System.out.println("Please select an option");
				System.out.println("\t1.Alkane ");
				System.out.println("\t2.Alkene ");
				System.out.println("\t3.Alkyne ");
				System.out.println("\t4.Exit");
				selector = input.nextInt();
				runner = false;
			}catch(Exception e){
				System.out.println("Invalid Input");
				selector = 0;
				input.nextLine();
				runner = true;

		}

	}