Parallel port program fail

I'm new to programming. Anyway, I've read about the inpout32.dll thing from http://www.logix4u.net/ site
1stly I'm not sure if I placed it in the right place, but anyway when I try to run the program in Win XP, it fails.

Any idea how to overcome this problem?

#include
#include

int _outp( unsigned short port, int databyte );

// This program accepts an input from the user
// in decimal and outputs that number as an 8-bit
// binary number to the port at 378 hex, usually
// LPT1

int main () {

int inval = 0;

while ( inval < 256) {
printf("Enter a value in decimal (256 to quit)>");
scanf("%d", &inval);

_outp(0x378, inval);
}

_outp(0x378, 0);

return 0;
}

this is a simple program I gotten from the web too.
It gves an error.