Thread: multiple header #includes

my program has multiple .cpp files. in each one, i want to include each of my multiple .h files. but for certain header files, when they are including more than once, i get a linking error, "function already defined in something.obj". Now, i could understand this normally, but in each header file, i've added the code to prevent redefinitions.

Code:

#ifndef cBenH
#define cBenH
...
...
...
#endif

here is the controversial header file.

Code:

#ifndef hListH
#define hListH

#include <windows.h>

//Function prototypes
void Notify(HWND,LPCTSTR);
void Notify(HWND,long int);

//Functions
void Notify(HWND hwnd,LPCTSTR str)
{
	MessageBox(hwnd,str,"Notification",MB_OK);
	return;
}

void Notify(HWND hwnd,long int num)
{
	char *chTemp;

	chTemp=(char *)malloc(11);
	ltoa(num,chTemp,10);

	Notify(hwnd,chTemp);

	free(chTemp);
	return;
}

#endif

why is the code being processed more than once?