void display()
{
switch(num)
{
case 1: display1();break;
case 2: display2();break;
case 3: display3();break;
case 4: display4();break;
case 5: display5();break;
case 6: display6();break;
case 7: display7();break;
case 8: display8();break;
case 9: display9();break;
default :display1();
}