VB语言的问题

Private Sub Text1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Text1.SelText <> "" Then
cmdcut.Enabled = True
cmdcopy.Enabled = True
cmdpaste.Enabled = False
Else
cmdcut.Enabled = False
cmdcopy.Enabled = False
cmdpaste.Enabled = True
End If
End Sub

我想知道在输入这些语言的时候，英文字母是不是要区分大小写？？

还有
Private Sub Form_Load()
cmdcut.Enabled = False
cmdcopy.Enabled = False
cmdpaste.Enabled = False
End Sub

Private Sub Text1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Text1.SelText <> "" Then
cmdcut.Enabled = True
cmdcopy.Enabled = True
cmdpaste.Enabled = False
Else
cmdcut.Enabled = False
cmdcopy.Enabled = False
cmdpaste.Enabled = True
End If
End Sub

Private Sub CmdClose_click()
End
End Sub

这些Private Sub.....每一段顺序不变，但是每一大段的顺序不是这样

函数，变量名，过程名之类的都不区分大小写
只有常数才区分大小写
比如：
End If
end if
END IF
这三种写法都可以
但是
binalian="aa"
和
binalian="AA"

就不一样

Private Sub Text1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Text1.SelText <> "" Then
cmdcut.Enabled = True
cmdcopy.Enabled = True
cmdpaste.Enabled = False
Else
cmdcut.Enabled = False
cmdcopy.Enabled = False
cmdpaste.Enabled = True
End If
End Sub

Private Sub CmdClose_click()
End
End Sub

这样可以

Private Sub CmdClose_click()
End
End Sub

Private Sub Text1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Text1.SelText <> "" Then
cmdcut.Enabled = True
cmdcopy.Enabled = True
cmdpaste.Enabled = False
Else
cmdcut.Enabled = False