Errors using GETPID()

GETPID() is a function that is part of the IFPORT module. I am using this function in a module called 'random.f90', which in-turn is USEd in the main program 'test_rand.f90'

1. Upon not USEing IFPORT, compilation of the moduled results in the following error:

   $ ifort -c random.f90
   random.f90(47): error #6404: This name does not have a type, and must have an explicit type.   [GETPID]
               pid = GETPID()
   ------------------^
   compilation aborted for random.f90 (code 1)

2.  But if I add a USE IFPORT statement at the beginning, the compilation goes through without any errors, but linking results in an error I don't understand:
   

   $ ifort random.mod test_rand.f90
   test_rand.f90(3): error #6406: Conflicting attributes or multiple declaration of name.   [RANDOM]
       USE random
   --------^
   compilation aborted for test_rand.f90 (code 1)

According to the IFPORT article, they are both valid way of using functions from the Portability module, but both run into errors. I am using the GETPID() function exactly as described in its Intel reference, with the variable 'pid' defined as an INTEGER.

Using Gfortran, the code compiles and runs correctly (of course, without the USE IFPORT statement), so, for portability, I would like to get it working without the explicit USE statement. Any ideas on what I might be doing wrong?