Graphics 800,600,32,2
SetBuffer (BackBuffer ())
Global x1%,y1%,x2%,y%,x3%,y3%,width%,height%
While Not KeyHit (1)
Cls ()
If MouseHit (1) Then x1 = MouseX() :y1 = 300;MouseY ()
If MouseHit (2) Then x2 = MouseX() :y2 = 300;MouseY ()
width = -(x1-x2)
height = width
x3 = x1
y3 = y1-(height/2.0)
Color 50,50,50
Oval x3,y3,width,height
Color 255,0,0
Plot x1,y1
Color 0,255,0
Plot x2,y2
Flip
Wend
End