title: procedure declaration does not match description of event or procedure having the same name
body: <p>I am just novice and I tried to make a simple program in Visual Basic 6. The code is almost equivalent to that in the textbook. It was meant to be a kind of a paint program. Surprisingly, it couldn't be compiled with the error given in the title of this question.
  This is the code:</p>
  
  <pre><code>Option Explicit
  
  Dim Col As Long
  
  Private Sub Form_Load()
      AutoRedraw = True
      BackColor = vbWhite
      Col = vbBlack
      DrawWidth = 3
  End Sub
  
  Private Sub Command1_Click()
      CommonDialog1.ShowOpen
      Form1.Picture = LoadPicture(CommonDialog1.FileName)
  End Sub
  
  Private Sub Command2_Click()
      CommonDialog1.ShowSave
      SavePicture Image, CommonDialog1.FileName
  End Sub
  
  Private Sub Command3_Click()
      CommonDialog1.ShowColor
      Col = CommonDialog1.Color
  End Sub
  
  Private Sub Form_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
      PSet (X, Y), Col
  End Sub
  
  Private Sub Toolbar1_ButtonClick(ByVal Button As MSComctlLib.Button)
      Select Case Button.Key
      Case "Line1"
          DrawWidth = 3
      Case "Line2"
          DrawWidth = 20
      End Select
  End Sub
  </code></pre>
  
  <p>The application crashes on the following line:</p>
  
  <pre><code>Private Sub Toolbar1_ButtonClick(ByVal Button As MSComctlLib.Button)
  </code></pre>
  
  <p>With the error:</p>
  
  <blockquote>
    <p>procedure declaration does not match description of event or procedure
    having the same name</p>
  </blockquote>