int modo_grafico(char ruta[80]) {
   /* request auto detection */
   int gdriver = DETECT, gmode, errorcode;
   /* initialize graphics mode */
   initgraph(&gdriver, &gmode, ruta);
   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk) {
      printf("Graphics error: %s\n", grapherrormsg(errorcode));
      printf("Press any key to halt:");
      getch();
      exit(1);             /* return with error code */
   }
return(0);
}