Private Sub Form_Activate()
 Dim x, y, z As Single
 Scale (-20, 20)-(20, -20)
 Line (0, 17)-(0, -17)
 Line (18, 0)-(-18, 0)
 For z = 0 To 15 Step 0.01
 y = z * Sin(z)
 x = z * Cos(z)
 PSet (x, y)
 Next z
 
 
End Sub