How to boost up fields to get priority based search

[nithin446]

I have the following index for searching full text.
{
"fulltext": {
"search": {
"index": "function(doc) { var ret=new Document(); ret.add(doc._id,{'field': '_id', 'boost': 2.0}); ret.add(doc.pid,{'field': 'pid', 'boost': 3.0}); ret.add(doc.artist_id,{'field': 'artist_id', 'boost': 3.0}); ret.add(doc.artist_name,{field:artist_name,'boost': 100.0}); ret.add(doc.object_title,{'field': 'object_title', 'boost': 300.0}); ret.add(doc.description ,{'field': 'description', 'boost': 80.0}); ret.add(doc.portfolio_info,{'field': 'portfolio_info'}); ret.add(doc.edition,{'field': 'edition'}); return ret }"
}
}
}

I need to get results from object_title shows first, then with artist_name, then show the remaining results.
Can you please help me where I am going wrong?