Error Compiling

Hi guys, I'm new to Arduino programming and got a problem I haven't figured a way to solve yet. I got this code for a temperature sensor on my board:

void loop()
{
int temperature;
float voltage;
float celcius;
temperature = analogRead(0);
voltage = (float)temperature/1023.05;
celcius = temperature
100.0-50.0;
Serial.println(voltage,2);
}

When I compile the code, I get a "Error compiling" message:

core.a(main.cpp.o): In function main': /Applications/Arduino.app/Contents/Resources/Java/hardware/arduino/cores/arduino/main.cpp:7: undefined reference to setup'

What am I doing wrong?

Thanks for any help!

You're missing a function called "setup".
Even if empty, it is required.

Where do I put it in?

Anywhere.
Just not inside another function.

Have a look at any of the examples if you're unclear.

Perfect! Thank you!