Error compiling

Sir I uses the INPUT_PULLUP but then I cant compile and the arduino said that INPUT_PULLUP was not declared. May I know why sir. Thanks

Sorry, my crystal ball broke.

What Arduino? What code? Which IDE version?

May I know why sir.

If you are using a pre-1.0 version of the IDE, then INPUT_PULLUP is not defined. What version are you using? What board do you have (selected)?

Oww. I am using version 1.0.1 ... ay what version could use that INPUT_PULLUP ??

Why are you using an ancient IDE? Just upgrade to 1.6.x

Strange... 1.0.1 is the first version with INPUT_PULLUP.

Anyway, there is no reason to use 1.0.1 besides archaeological interest.