在窗体中添加一个命令按钮(名为Command1),然后编写如下代码:
Public x as integer
Private Sub Command1_Click( )
a=10
Call s1
Call s2
MsgBox x
End Sub
Private Sub s1( )
x=x+20
End Sub
Private Sub s2( )
Dim x as integer
x=x+20
End Sub
窗体打开运行后,单击命令按钮,则消息框的输出结果是______。
A.10
B.30
C.40
D.50