初学Vb 有一段代码始终提示变量未定义 ，求高手鉴定指导 ！

我打算练习用代码首先自定义一个坐标系 再用Line 方法画好X轴Y轴 和 sin(x)正弦函数图象 。 代码我列在下面 。 我想问一下 为什么 第6行： Private Sub InitDraw() 始终在调试的时候提示变量未定义呢 ？？ 求教育啊 。。
Option Explicit
Const PI = 3.1415926
Private Sub Form_Load()
InitDraw
End Sub
Private Sub InitDraw()
picDraw.Scale (-1, 10)-(10, -10)
picDraw.CurrentX = -1
picDraw.CurrentY = 0
picDraw.Line (0, 10)-(10, 0)
picDraw.CurrentX = 0
picDraw.CurrentY = 10
picDraw.Line (0, 10)-(0, -10)
picDraw.CurrentX = 0
picDraw.CurrentY = 0

picDraw.CurrentX = 0
picDraw.CurrentY = 0
End Sub
Private Sub cmdDraw_Click()
Dim i As Double
Dim amp As Double
Dim freq As Double
Dim phase As Double

picDraw.Cls
InitDraw
amp = Trim(txtAmp.Text)
freq = Trim(txtFre.Text)
phase = Trim(txtPhase.Text)
For i = 0 To 2 * PI Step 0.01
picDraw.Line -(i, amp * Sin(freq * i * phase))
Next i
End Sub

在Form1上添加1个PictureBox控件命名为picDraw,并设置其AutoRedraw属性为True
再要添加1个按钮控件命名为cmdDraw
添加3个TextBox控件分别命名为txtAmp,txtFre,txtPhase

LZ的书本代码有错误:
修改如下
Option Explicit
Const PI = 3.1415926
Private Sub Form_Load()
InitDraw
picDraw.AutoRedraw = True
End Sub

Private Sub InitDraw()
picDraw.Scale (-1, 10)-(10, -10)
picDraw.CurrentX = -1
picDraw.CurrentY = 0
picDraw.Line (0, 10)-(10, 0)
picDraw.CurrentX = 0
picDraw.CurrentY = 10
picDraw.Line (0, 10)-(0, -10)
picDraw.CurrentX = 0
picDraw.CurrentY = 0

picDraw.CurrentX = 0
picDraw.CurrentY = 0
End Sub

Private Sub cmdDraw_Click()
Dim i As Double
Dim amp As Double
Dim freq As Double
Dim phase As Double

picDraw.Cls
InitDraw
amp = Val(txtAmp.Text)
freq = Val(txtFre.Text)
phase = Val(txtPhase.Text)
For i = 0 To 2 * PI Step 0.01
picDraw.Line -(i, amp * Sin(freq * i * phase))
Next i
End Sub

你好！ PicDraw定义了吗？ 普通的变量可以隐式声明，但是像数组、结构体是不可以的。 ……Scale？？？是VB .Net??? 如果对你有帮助，望采纳。