Complete the basic form submission function of the information release page;
Complete non-empty inspection of input information;
AddMsg.asp -> msg_add.asp
Demsg.asp -> msg_del.asp
Showmsg.asp -> msg_edit.asp
Updatemsg.asp -> msg_list.asp
News.bdate -> news.sdate
Need to resolve the correctness check of information effective time
Need to resolve the processing that the user ID already exists does not set the validity period, news.sdate and news.edate are left blank.
