[b_mallerd]

It means you need to either define your function or else prototype it.

In a header file you need to type in something like this...


int funtion_name(int parameter_names);

and then in a file you need to actually define the function...

int function_name(int parameter_name)
{
your code goes here;
}


Make sure you have both parts and also make sure you have the header file included in whatever .c file that you are calling the function from.

incase you dont knoe calling = executing your function.

Hope this helps.