Code:
TRISA=255  ' Set all PORTA pins to Input

dip var byte

Start:
    dip=PORTA
    select case dip
        case 0
            '
            ' Code for PORTA=0
            '
        case 1
            '
            ' Code for PORTA=1
            '
        case 2
            '
            ' Code for PORTA=2
            '
        end select
    goto start
And you're using a BYTE sized variable to do it.