Does End Using close an open SQL Connection

using cn as new system.data.sqlclient.sqlconnection()
    cn.open
    '{do a bunch of other stuff with commands and datareaders here}
    cn.close 'Do I need this?
end using

Try
    SqlConnection cn as new system.data.sqlclient.sqlconnection()
    cn.open
    '{do a bunch of other stuff with commands and datareaders here}
    cn.close 'Do I need this?
Finally
    cn.Dispose()
End Try