main()
{
float x, y;
int event;
char key;

   ustart("high2",30.,600.,100.,300.);
   upset("colo",1.0);
   uprint(5.,80.,"Place cursor in yellow area");
   uprint(5.,75.,"and press left mouse button.");
   udarea(50.,80.,50.,100.);
   uwindo(0.,50.,0.,50.);
   upset("colo",5.0);
   uset("fill");
   uoutln();
   uset("nofi");
   upset("colo",4.0);
   while (1){
      ugrin(&x,&y);
      umove(x-5.0,y);
      udraw(x+5.0,y);
      umove(x,y-5.0);
      udraw(x,y+5.0);
      uset("fill");
      uplygn(x,y,4.0,4.0);
      upset("nofi");
   }
}