i have 2 .cpp (engine.cpp, main.cpp) files in myproject that use these timers and when i include the .h file, i get redefinition errors for the timers

how do i get these timers to (or at least the variables) to be used in both cpp files?

this is the basic layout
----------------
in main.cpp
----------------
#include timers.h
#include engine.h

code

--------------
in engine.cpp
--------------
#include engine.h
code

--------------------
in engine.h
--------------------
#include timers.h
code

--------------
and in timers.h
----------------
#ifndef _TIMERS_
#define _TIMERS_
volatile double SECONDS=0;//seconds - keeps track of time elapsed in game
void SECONDS_TIMER()
{
SECONDS=SECONDS+.001;
}
END_OF_FUNCTION(SECONDS_TIMER);
volatile int FPS_T_V=0;
volatile int LAST_FPS=0;
void FPS_T()//used to calculate frames per second
{
LAST_FPS=FPS_T_V;
FPS_T_V=0;
}
END_OF_FUNCTION(FPS_T);
#endif

yeah, if i dont, i cant access those variables from main.cpp because im using a multiple file project in MSVC++ 6

Generally, functions shouldn't be in .h files, unless they're inline functions. And callbacks shouldn't be inline functions.

Also, variables declared in .h files should be labeled extern, and have a .c or .cpp also declare a variable of the same name without the extern.

Otherwise, ever .c or .cpp files that includes those .h files will create a variable or function by that name, and all the variables and functions will conflict with each other.

Correct.

Another thing: I'm not sure, but I seem to recall floating point numbers not working from inside of timer functions on some platforms. If you don't need portability, maybe it's not an issue.