Lost In The Docs / Data Merge

Question

Hey,
I'm trying to cook up a script that would add one of the items in my "data merge" into a text frame.
I have the code below, and I'm trying to understand the scripting help file, but so far I was only able to output some kind of resolve(....) text.
The "310-7251" is a name of one item in my data merge list. I want the text frame to contain it's.. um.. reference(?), the "<< 410-7251 >>" text that I would get if I did this manually, that would turn into the field's value when I would create a merged document.
What am I doing wrong?
var doc     
= app.documents.add();
var text_frame = doc.pages[0].textFrames.add();
text_frame.geometricBounds = [
'0pt', '115pt', '240pt', '240pt',
doc.dataMergeProperties.selectDataSource('E:/Temp/Merge-Test.csv');
text_frame.parentStory.insertionPoints[-1].contents += doc.dataMergeTextPlaceholders.item('310-7251').toSpecifier();

Answer 1

Well, I gave up and wrote a function that would traverse all the items and find the one I want.
With my extremely limited knowledge of the language, it seems there's a bug with the item() method; it doesn't accept field name string properly.
Here's my code that finally worked, but I'd love to know what I was doing wrong.. Thanks.
var doc          = app.documents.add();
var text_frame = doc.pages[0].textFrames.add();
text_frame.geometricBounds = [
    '0pt', '115pt', '240pt', '240pt',
doc.dataMergeProperties.selectDataSource('E:/Temp/Merge-Test.csv');
doc.dataMergeTextPlaceholders.add(
    text_frame.parentStory,
    text_frame.parentStory.insertionPoints[-1],
    get_field('310-7251', doc)
function get_field(field_name, doc) {
    var fields = doc.dataMergeProperties.dataMergeFields;
    for ( var i = 0, l = fields.length; i < l; i++ ) {
        if (fields[i].fieldName == field_name) {
            return fields[i];
    alert('Error: did not find any fields with name ' + field_name);