getmaxx function in c

#include<graphics.h>
#include<conio.h>
 
main()
{
   int gd = DETECT, gm, max_x;
   char array[100];
 
   initgraph(&gd,&gm,"C:\\TC\\BGI");
 
   max_x = getmaxx();
 
   sprintf(array, "Maximum X coordinate for current graphics mode and driver = %d.",max_x);
   outtext(array);
 
   getch();
   closegraph();
   return 0;
}