Compile error with Blink program

I just got hooked up and am trying to run the Blink program. When I verify it I get no compilation errors. But then when I go to upload it to my board I get the following:

C:\arduino\arduino-0018\hardware\arduino\cores\arduino/main.cpp:7: undefined reference to `setup' C:\arduino\arduino-0018\hardware\arduino\cores\arduino/main.cpp:10: undefined reference to `loop'

I changed nothing in the code. Any insights?

I'm using IDE v18 btw.

I got this a few weeks back (for some much more complex code mind you) but I was also confused.

Is the board selected correctly? It might be that some core files are missing maybe?