PIC18f2455 blink

[iugmoh]

I try this code for blinking led on PIC18f452 , but nothing happened, the led always off , I use in this circuit 4MHZ XT crystal , 10K connected to MCLR TO +5v:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;
trisb=0

main:
portb=0
pause 1000

portb=255
pause 1000

goto main

end

;;;;;;;;;;;;;;;;;;;;;;;;;

Here is 18F452.INC file
;************************************************* ***************
;* 18F452.INC *
;* *
;* By : Leonard Zerman, Jeff Schmoyer *
;* Notice : Copyright (c) 2005 microEngineering Labs, Inc. *
;* All Rights Reserved *
;* Date : 12/16/05 *
;* Version : 2.47 *
;* Notes : *
;************************************************* ***************
NOLIST
ifdef PM_USED
LIST
"Error: PM does not support this device. Use MPASM."
NOLIST
else
LIST
LIST p = 18F452, r = dec, w = -311, w = -230, f = inhx32
INCLUDE "P18F452.INC" ; MPASM Header
__CONFIG _CONFIG1H, _OSCS_OFF_1H & _XT_OSC_1H
__CONFIG _CONFIG2H, _WDT_ON_2H & _WDTPS_128_2H
__CONFIG _CONFIG4L, _LVP_OFF_4L
NOLIST
endif
LIST
EEPROM_START EQU 0F00000h
BLOCK_SIZE EQU 8

[skimask]

I try this code for blinking led on PIC18f452 , but nothing happened, the led always off , I use in this circuit 4MHZ XT crystal , 10K connected to MCLR TO +5v:

Connect the LED to MCLR...does it work then?
And let it run for at least 2 minutes.
Does the LED on PortB.0 change state?

[iugmoh]

when I connect Led to MCLR it work but with very low brightness, nothing happened to portb.0

[skimask]

yes it work but with very low brightness

What works?
MCLR or PortB.0?
Does it flash?
What's the value of your resistor?

[iugmoh]

oky , I connect MCLR -------> led through 470 ohm resistor , the brightness is very low, nothing happened to portb always off

[skimask]

oky , I connect MCLR -------> led through 470 ohm resistor , the brightness is very low, nothing happened to portb always off

The point of the LED on MCLR was to make sure that MCLR was actually getting pulled up to +5v.