text as query of search

[Giovanni Caputo]

Hi,
how  can i get documents similar to a long text??

I am using lucene.net 2.4

I have tested to use Query query = parser.Parse(ua.TestoCompleto);
where ua.TestoCompleto is a String


I have created QueryParser parser = new QueryParser(INDEX_PATH, analyzer);
as same mode of indexwriter


but it generate this exception

A first chance exception of type 'Lucene.Net.QueryParsers.ParseException' 
occurred in Lucene.Net.dll
Encountered ":" at line 1, column 0.
Was expecting one of:
    <NOT> ...
    "+" ...
    "-" ...
    "(" ...
    <QUOTED> ...
    <TERM> ...
    <PREFIXTERM> ...
    <WILDTERM> ...
    "[" ...
    "{" ...
    <NUMBER> ...