Code:
@ device HS_OSC,MCLR_OFF,LVP_OFF,WDT_OFF,PROTECT_OFF
DEFINE OSC 4
'Use b1 to hold pulse width variable for servo 1
b1 var byte
'initialize variables
b1 = 150
low portb.0		' put the servoport low.
main:
        low portb.0
	pulsout portb.0, b1		'send current servo 1 position out
	if porta.0 = 0 then left1	'check for pressed switch 0
	if porta.1 = 0 then right1	'check for pressed switch 1
	if b1 > 150 then
               b1 = b1 - 1
        else
               b1 = b1 + 1
        endif
        pause 18 : goto main
left1:  b1 = b1 + 1 : if b1 >254 then max1
	goto main
right1:  b1 = b1 - 1 : if b1 <75 then min1
	goto main
max1:  b1 = 75 : goto main
min1:  b1 = 254 : goto main
END
This should go left with one button, go right with the other button, and if no buttons are pressed, should 'walk' back to center.
Note the BOLDED statements