while ( 1 ) 
   { 
      hPipe = CreateFile( 
         lpszPipename,   // pipe name 
         GENERIC_READ |  // read and write access 
         GENERIC_WRITE, 
          0 ,              // no sharing 
         NULL,           // default security attributes
         OPEN_EXISTING,  // opens existing pipe 
          0 ,              // default attributes 
         NULL);          // no template file 
 
   // Break if the pipe handle is valid. 
 
      if (hPipe != INVALID_HANDLE_VALUE) 
         break; 
 
      // Exit if an error other than ERROR_PIPE_BUSY occurs. 
 
      if (GetLastError() != ERROR_PIPE_BUSY) 
      {
         printf("Could not open pipe"); 
         return  0 ;
      }
 
      // All pipe instances are busy, so wait for 20 seconds. 
 
      if (!WaitNamedPipe(lpszPipename,  20000 )) 
      { 
         printf("Could not open pipe"); 
         return  0 ;
      } 
   }