void setup()  
{   
  size(600,600);  
  background(255);  
  smooth();  
} 

void draw()  
{   
  ellipseMode(CENTER);
  ellipse(mouseX,mouseY,abs(mouseX-pmouseX),abs(mouseX-pmouseX));
  //line(mouseX+80,mouseY-80,pmouseX,pmouseY);
} 


void mousePressed() 
{
  background(255);
}