'create a new project
'paste the following code into the (General)(Declarations)
'

Dim DrawSwitch As Integer
Dim r As Integer, g As Integer, b As Integer

Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
    
    DrawSwitch = DrawSwitch - 1
    
    Select Case Button
    
        Case vbLeftButton
            r = 255
            g = 0
            b = 0
                 
        Case vbMiddleButton
            r = 0
            g = 255
            b = 0

        Case vbRightButton
            r = 0
            g = 0
            b = 255
            
    End Select
    
    CurrentX = X
    CurrentY = Y
    
End Sub

Sub Form_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)

    If DrawSwitch Then
        Line -(X, Y), RGB(r, g, b)
    End If
    
End Sub

Sub Form_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
    
    DrawSwitch = 0
    
End Sub