Alternate way to draw a circle

[axipher]

Well I am using fb and this is what I did:

Code:

Declare Sub DrawEllipse (x AS INTEGER, y AS INTEGER, xr AS INTEGER, yrAS INTEGER, colour AS INTEGER)

Screen 13,,,1

DrawEllipse 160, 100, 80, 60, 15
Sleep

SUB DrawEllipse (x AS INTEGER, y AS INTEGER, xr AS INTEGER, yrAS INTEGER, colour AS INTEGER)
FOR xl = xr TO 0 STEP -1
  yl = SQR(xr * xr - xl * xl) * yr / xr: Y2 = yl
  DO
    Pset (x + xl, y + yl), colour
    Pset (x - xl, y + yl), colour
    Pset (x + xl, y - yl), colour
    Pset (x - xl, y - yl), colour
    yl = yl - 1
  LOOP WHILE yl > Y1
  Y1 = Y2
NEXT
END SUB