TEMPERATURE SENSOR 18B20 WITH ARDUINO

I am currently writing this simple code to check the temp sensor
[code]#include <One Wire . h> int DS18S20_Pin = 2; //DS18S20 Signal pin on digital 2 //Temperature chip i/o OneWire ds(DS18S20_Pin); // on digital pin 2 void setup(void) { Serial.begin(9600); } void loop(void) { float temperature = getTemp(); Serial.println(temperature); delay(100); //just here to slow down the output so it is easier to read }[/code] I m getting "sketch_feb27a:14: error: 'getTemp' was not declared in this scope"
can someone tell me why?