exist method on temporary table

[ist]

Hi,
I'm trying to make exist method on temporary table something like this...

static boolean exist(MyTempTable _tempTable,
                             RefTableId      _tableId,
                             RefRecId        _recId)
{
    return _tableid && _recId && (select RecId from _tempTable
                                                   where _tempTable.TableNum = _tableId
                                                       && _tempTable.RecordNo = _recId
             ).RecId != 0;
}

Just like find() methods on a temp table, I pass the temporary table reference as parameter, but compiler throw an error "The table _tempTable does not exist".

Any ideas what's the problem?