C++: Set Registry Key Values

This piece of example code writes a key to the windows registry.

#include <windows.h>

int SetRegValue(char *key_name,char *key_word,char *b,int dwType,int s)
{
  int j=0;

  DWORD lpdwDisposition;
  HKEY hKey;

  j=RegCreateKeyEx(
                    HKEY_CURRENT_USER,
                    key_name,
                    0,                       /* reserved */
                    NULL,                    /* address of class string */
                    REG_OPTION_NON_VOLATILE, /* special options flag */
                    KEY_WRITE,               /* desired security access */
                    NULL,                    /* address of key security structure */
                    &hKey,                   /* address of buffer for opened handle */
                    &lpdwDisposition         /* address of disposition value buffer */
                  );

  if (j==ERROR_SUCCESS)
  {
      RegSetValueEx(hKey, key_word, 0, dwType, (unsigned char *)b, s);
      RegCloseKey(hKey);
  }
  return(j);
}

int main(int argc, char* argv[])
{
  char val[100]="myusername";
  SetRegValue("Software\\MySoft\\Settings","Username", val, REG_SZ, 100);
  return 0; 
}

source(s): http://msdn2.microsoft.com/en-us/library/ms724923.aspx
http://msdn2.microsoft.com/en-us/library/ms724875.aspx