if isnull(me.编号) then
msgbox "请输入编号"
me.编号.SetFocus
exit sub
end if
if isnull(me.名称) then
msgbox "请输入名称"
me.名称.SetFocus
exit sub
end if
if isnull(me.单号) then
msgbox "请输入单号"
me.单号.SetFocus
exit sub
end if
if isnull(me.日期) then
msgbox "请输入日期"
me.日期.SetFocus
exit sub
end if