microcontroller to Ultrasonic

[emperror123]

hi all
currently i have problem with the code below

#define XTAL_FREQ 20MHZ

#include <pic.h>
#include <htc.h>
#include "delay.h"
#include "lcd.h"
#include <stdio.h>
#include <stdlib.h>

__CONFIG(0x3f3A); 

void pic_init();
void getRange();

#define trigg RC3
#define echoo RC2
//#define PIR RC1			//INDICATE RA0 as "PIR"


//global variable
unsigned char time;
float width;
float distance = 0;
char s[32];

void main()
{
    pic_init();
    lcd_init();

    while (1)
	{
        getRange();
		while(distance > 15 && distance < 25)
		{
			RB7=1;
			DelayMs(1000);  //1 second for hand to move to IR sensor
//			while(1)
//			{
				getRange(); 
				if(distance > 0 && distance < 10)  //enter
				{
					//PORTA=0x00;
					RA1=1;
					DelayMs(900);
					break;
				}
				while(distance > 25 && distance < 400)  //hand out of operating range
				{	
					if(RD2 == 1)    // up
					{
					//	PORTA=0x00;
						RA2=1;
						DelayMs(900);
						break;
					}
					if(RD3 == 1)    // left
					{
					//	PORTA=0x00;
						RA3=1;
						DelayMs(900);
						break;
					}
					if(RD0 == 1)   // down
					{
					//	PORTA=0x00;
						RC0=1;
						DelayMs(900);
						break;
					}
					if(RD1 == 1)  // right
					{
					//	PORTA=0x00;					
						RA5=1;
						DelayMs(900);
						break;
					}
					else
					{
						PORTA = 0X00;
						PORTC = 0x00;
						break;
					}
				}
			}
			break;
		}	
    }
//}

void pic_init()
{
    TRISA = 0;
	PORTA = 0;

    TRISB = 0;
    PORTB = 0;

	TRISC = 0b00110100;
	PORTC = 0;

	TRISD = 0xff;
    PORTD = 0;

	TRISE = 0x00;
    PORTE = 0;

	CMCON=0x07;
	ADCON1=0;
}

void getRange()
{
    time = 0;
    TMR1H = 0;
    TMR1L = 0;
    trigg = 1;    		// Trigger to receive pulse.
    DelayUs(20); 		// Delay 20us to ensure sensorfully initiate.
    trigg = 0;    		// Turn off trigger.

    while(!echoo){} 	// continue

    T1CON=0b011001; 	// timer1 on (prescale 1:8), pg59

    while(echoo){} 		// continue

    T1CON = 0;        // timer1 off

    width = (( TMR1H << 8 ) | TMR1L );
	width = 0xFFFF - (0xFFFF - width);
	width = width * (0.0000004);
	distance = (width * 1000000)/ 58;

//    sprintf( s , "%f cm" , distance);
//	lcd_clear();
//    lcd_puts(s);
//	DelayMs ( 250 );
//	DelayMs ( 250 );
}

from the above code, i found that my Ultrasonic having problem where sometimes i get 0cm from LCD, but when i have detect certain range, it become 0cm after that, what shud i done inorder to solve the problem

thank