First code:
You don't need the GOTO Off... it will jump there anyway

Second code:
Wait and Off are reserved word, so you need to change them
Code:
GOTO Wait_Again    '******* not needed

Wait_Again:                   'waits for low signal
Code:
Wait:                              'wait for high signal
     INPUT PORTA.0 '***** this one you don't need it as it's 
                   ' already defined above
Code:
Wait_Again:                   'waits for low signal
     INPUT PORTA.0 '******* same thing here
another method
Code:
'---------- SIDE TWO PICS' CODE
X VAR BYTE
ADCON1 = 7  'sets all as digital
PORTB = 0  'clears all port pins
PORTC = 0
TRISB = 0  'sets all as outputs
TRISC = 0
TRISA.0 = 1  'set as input

Start:
     While PORTA.0=0 : Wend ' wait 'till PORTA.0=1

     FOR X = 0 TO 15
          HIGH X
          PAUSE 200
          NEXT X

     While PORTA.0=1 : Wend 'waits for low signal

     FOR X = 0 to 15
         LOW X
         PAUSE 200
         NEXT X

    goto start