Rookie question

[sacastil]

Hi, I just started playing around with PIC chips and I've been having some trouble figuring out the sample code from the website.
I'm using an 18F4620 and I was looking at the button command sample, where the 3 LEDs on the X2 board will start flickering once a button is pushed.
Here's the code, just in case,

Define LOADER_USED 1

button1 VAR PORTB.4
button2 VAR PORTB.5
button3 VAR PORTB.6

LED1 VAR PORTB.0
LED2 VAR PORTB.1
LED3 VAR PORTB.2

B1 VAR BYTE 'Working buffer 1 for button command
B2 VAR BYTE 'Working buffer 2 for button command
B3 VAR BYTE 'Working buffer 3 for button command

Clear 'Clear buffers
PORTB = 0 'LEDs off

TRISB = %11110000 'Set portb 0-3 outputs, 4-7 inputs
' OPTION_REG.7 = 0 'Enable PORTB pull-ups



chk1: Pause 25
Button button1,0,40,5,B1,0,chk2 ' Check Button 1 (Skip to 2 if Not Pressed)
Toggle LED1 ' Toggle LED if pressed

chk2: Button button2,0,40,5,B2,0,chk3 ' Check Button 2 (Skip to 3 if Not Pressed)
Toggle LED2 ' Toggle LED if pressed

chk3: Button button3,0,40,5,B3,0,chk1 ' Check Button 3 (Skip to 1 if Not Pressed)
Toggle LED3 ' Toggle LED if pressed

GoTo chk1 ' Do it forever

I found that the chip I'm using does not support the OPTION_REG function and I've been looking for a similar function in the chip manual but didn't find anything or perhaps I wasn't looking at the right place.
Could anyone suggest anything? or help me out?
Thank you.

[skimask]

I found that the chip I'm using does not support the OPTION_REG function and I've been looking for a similar function in the chip manual but didn't find anything or perhaps I wasn't looking at the right place.
Could anyone suggest anything? or help me out?
Thank you.

Yes, open the datasheet in Adobe Acrobat Reader...
Hit Ctrl-F (for find), and type the word
weak
in the search box.
Alternatively, the phrase
pull-up
would get you a long way too.