Private Sub Command1_Click()
If (IsNumeric(txt.Text) = False) Then
lbl.Caption = "请输入重量"
Else
Select Case Val(txt.Text)
Case Is > 3
lbl.Caption = "请支付" & Val(txt.Text) + 2 & "元"
Case Is = 0
lbl.Caption = "别开玩笑了,请输入重量"
Case Else
lbl.Caption = "请支付5元"
End Select
End If
End Sub