help with ultrasonic code

I am using the following ultrasonic sensor.
Sunrom Electronics...
I tried to program it using arduino atmega8. First what i did is for the 5v pin in ultrasonic sensor i powered it using the digitalpin. Then i read the serial port and converted the buffer to ascii. but the problem what i get is values remaining constant though obstacles placed at different positions.here is the code what ive used:
int ser=0;
char s;
char st[10];
int pin=2;
int a;
int i=0;
int range;
void setup()
{
pinMode(pin,OUTPUT);
Serial.begin(9600);
}
void loop()
{
digitalWrite(pin,HIGH);
delay(1000);
digitalWrite(pin,LOW);
delay(1000);
/* for(i=0;i<10;i++)
{
s*=Serial.read();*
_ range=(s[0]-0x30)100;// I also tried these lines as given in the datasheet._
_ range=range+(s[1]-0x30)10;_
_ range=range+(s[2]-0x30)1;_
_ Serial.println(s
);
_
_
}_
_}/_

if(Serial.available())
{
* s=Serial.read();*
* if(i<10&&s!='c'&&s!='m')*
{
_ st*=s;
i++;
}
i=0;
int val=atoi(st);
Serial.println(val);
}
}*_

Your link is broken.

Could you modify your post, highlight all the code in it and then hit the "#" button on the editor toolbar, please?

If you're powering the device for a second, how much data does it return in that time?
The serial buffer is only 128 bytes long, so you may well be overflowing.

int ser=0;
char s;
char st[10];
int pin=2;
int a;
int i=0;
int range;
void setup()
{
pinMode(pin,OUTPUT);
Serial.begin(9600);
}
void loop()
{
digitalWrite(pin,HIGH);
delay(1000);
digitalWrite(pin,LOW);
delay(1000);
/* for(i=0;i<10;i++)
{
  s[i]=Serial.read();
  range=(s[0]-0x30)*100;// I  also tried these lines as given in the datasheet.
  range=range+(s[1]-0x30)*10;
  range=range+(s[2]-0x30)*1;
  Serial.println(s[i]);
}
}*/
 
if(Serial.available())
{
  s=Serial.read();
  if(i<10&&s!='c'&&s!='m')
{
    st[i]=s;
    i++;
}
   i=0;
    int val=atoi(st);
  Serial.println(val);
}
}

for a second it returns one data.. i mean the 9 characters(distance) as specified in the datasheet. the problem is that i am getting random values and at one instant the values become constant irrespective of the distance. if the serial buffer gets full as you say, what modification should i do in the code?pls help me

The link is still broken.
One way of preventing the buffer overflowing is to not allow it to.
You could switch on the rangefinder for a shorter period of time, but there may be a minimum time that it needs to be on to calibrate and start-up.
You could maybe flush the input buffer.
But witout a description of the device, who knows?

hi groove..for overflowing of the buffer...wil Serial.flush() wil do??..

this is the link...are u getting it??