This program stores the coordinates of the points drawn in the PointX and PointY arrays.

Private PointX() As Single
Private PointY() As Single
Private NumPoints As Integer

Private Drawing As Boolean

Private Sub Form_MouseDown(Button As Integer, Shift As _
    Integer, X As Single, Y As Single)
    ' Let MouseMove know we are drawing.
    Drawing = True
    
    ' Start from scratch
    NumPoints = 0
    Cls

    ' Start drawing here.
    CurrentX = X
    CurrentY = Y
End Sub

Private Sub Form_MouseMove(Button As Integer, Shift As _
    Integer, X As Single, Y As Single)
    ' Make sure we are drawing.
    If Not Drawing Then Exit Sub

    ' Save the new point.
    NumPoints = NumPoints + 1
    ReDim Preserve PointX(1 To NumPoints)
    ReDim Preserve PointY(1 To NumPoints)
    PointX(NumPoints) = X
    PointX(NumPoints) = X

    ' Draw to the point.
    Line -(X, Y)
End Sub

Private Sub Form_MouseUp(Button As Integer, Shift As _
    Integer, X As Single, Y As Single)
    ' Stop drawing.
    Drawing = False
End Sub