void setup() {
size(500,500);
background (0);

}
void draw () {
smooth ();
stroke (128,128,128,8);
strokeWeight (1);
noFill();
line (70,70,mouseX,mouseY);
line (mouseX,mouseY,70,430);
line (mouseX,mouseY,430,430);
line (mouseX,mouseY,430,70);
line (500,250,mouseX,mouseY);
line (mouseX,mouseY,250,500);
line (mouseX,mouseY,0,250);
line (mouseX,mouseY,250,0);
stroke (256,128,128,4);
fill (256,128,128,4);
ellipse (mouseX,mouseY,8,8);

}