编写VB程序，实现如下功能？

在文本框text1中输入一个二进制数，单击command1按钮，labell中显示转换成十进制后的结果。

Private Sub Command1_Click()

If Len(Text1.Text) > 0 Then Label1.Caption = "Dec: " & BIN_to_DEC(Text1.Text)

End Sub

Public Function BIN_to_DEC(ByVal Bin As String) As Long

Dim i As Long

For i = 1 To Len(Bin)

BIN_to_DEC = BIN_to_DEC * 2 + Val(Mid(Bin, i, 1))

Next i

End Function