ROOM MEMBERS ONLY
<iq to='NAMA_ROOM@conference.a.buzzmechat.com' type='set'><query xmlns='http://jabber.org/protocol/muc#owner'><x type='submit' xmlns='jabber:x:data'><field var='FORM_TYPE'><value>http://jabber.org/protocol/muc#roomconfig</value></field><field var='muc#roomconfig_roomname'><value>NAMA_ROOM</value></field><field var='muc#roomconfig_membersonly'><value>1</value></field></x></query></iq>