pulse width moduration(PWM) for lcd 2 line For Basic PRO Compiler

@ device pic16f877
define  osc 4
define  adc_bits 8
define  adc_clock 3
define  adc_sampleus 50
Define  LCD_DREG   PORTD   ' Define LCD connections
Define  LCD_DBIT   4
Define  LCD_RSREG  PORTD
Define  LCD_RSBIT  1
Define  LCD_EREG   PORTD
Define  LCD_EBIT   0 
RW      var        portd.2
low     RW         'LCD R/W low = write
trisa = $ff 
trisd = $00  
adcon1 = 0
num var  word      
LCDOUT $FE,1,"lcd_read" 
pause 3000
while(1)
    gosub read_value 
    gosub display
    pause 200
wend	
End
display:   
    LCDOUT $FE,$80," setting value  "
	Pause 20
	LCDOut $FE,$C0,"temp_set1=",dec4 num ," 'C" 
	Pause 20

return	

read_value:
    adcin 1,num
    pause 10
    if(num>254)then num=254
    hpwm 1,num,1000    
return