Programme PIC 16F877

unsigned long val=0;
unsigned short count=0;
unsigned short cm=0;
unsigned int count1=0;
char txt[12];
sbit LCD_RS at RB2_bit;
sbit LCD_EN at RB3_bit;
sbit LCD_D7 at RB4_bit;
sbit LCD_D6 at RB5_bit;
sbit LCD_D5 at RB6_bit;
sbit LCD_D4 at RB7_bit;


sbit LCD_RS_Direction at TRISB2_bit;
sbit LCD_EN_Direction at TRISB3_bit;
sbit LCD_D7_Direction at TRISB4_bit;
sbit LCD_D6_Direction at TRISB5_bit;
sbit LCD_D5_Direction at TRISB6_bit;
sbit LCD_D4_Direction at TRISB7_bit;

void interrupt(){
if(intcon.INTF==1){
tmr1l=0;
tmr1h=0;
t1con.rb0=1;
intcon.INTF=0;
}
else if(pir1.tmr1if==1){
count=count++;

  pir1.tmr1if=0;
}

}

void main() {
TRISB=0X01;
portb=0x00;
intcon.inte=1;
intcon.rb6=1;
Lcd_Init();
Lcd_Cmd(_LCD_CLEAR);
//Lcd_Cmd(_LCD_CURSOR_OFF);
 lcd_out(1,1,"distance:");
pie1.rb0=1;
pir1.rb0=0;
intcon.gie=1;
option_reg=0b11000000;
t1con=0b00000000;

for(;;){
if(portb.rb0==0){
t1con.rb0=0;
 count1=tmr1h;
 count1=count1<<8;
 count1=count1|tmr1l;
 val=count*65536;
 val=val+count1;
 val=val/1000;
 val=val/1000;
 val=val/1000;
 val=val/1000;
 val=val*122.5;
 LongToStr(val, txt);
 lcd_out(2,1,txt);