compiler construction - Knowing if the code is compiled using Lazarus or Delphi -

I am trying to put a code that can be compiled by Laser and Delphi without changing it, but its It will be like checking a conditional statement or something that is being used by the compiler. So whether any instructions or anything is possible, it is possible to know whether any code is being compiled with either Laser or Delphi?

The answer to this question was made available in the comment, I will make a copy of the original bit here:

Use {$ IFDEF FPC} to detect FreePascal.