CKEditor Plug-In: Getting text of drop-down item

I created a plug-in for CKEditor that opens a dialog with a drop-down. In that drop-down is a list of files the user has uploaded outside of CKEditor. The plan is to insert a "tag" into the text containing that filename, something like [[myfile.pdf]] and then when I display the actual page, I will insert a link to that file.

The problem is that the drop-down box being created by CKEditor is listing the filename (properly) but when I select it, it inserts the file's SIZE into the text rather than the filename. When the plug-in runs, it does an ajax call and grabs a directory listing of the user's files, which is where that number comes from; I think it's confusing it with a file ID.

Here's the meat of the plug-in. I left out the ajax call for brevity. It populates the variable "items."

EDIT: I modified the results returned from the ajax call to just return the filename, and then to return the filename (twice) using two different column names (name and filename) and in both cases, the inserted value was NULL. It just doesn't want to insert a text value it seems.

I also tried changing the values of id: under contents and also under elements (alternately) between tab-basic and linkType, and I got an error in the JS console about cannot read property getValue of undefined. Curses, foiled again!

ANOTHER EDIT: I tried putting the names of the files in a database table and I return that to the plug-in instead of the directory listing. If I select filename, attachmentid (in that order), the OPTION box lists the attachmentid, and inserts the filename. If I select attatchmentid, filename it will do it the exact opposite. So then I thought, gee, what if I selected the filename twice? So I did select filename, filename as filename2. And it works! This still isn't an ideal solution so I'm hoping somebody will know the proper way to do it.

CKEDITOR.dialog.add('attachfileDialog',function(editor){
return {
    title:'Attach File',
    minWidth:400,
    minHeight:200,
    contents:[{
        id:'tab-basic',
        label:'Choose File',
        elements:[{
            type:'select',
            id:'linkType',
            label:'Choose File',
            items:items,
            'default':''
        }]
    }],
    onOk:function(data){

        var dialog = this;
        var componentType = dialog.getValueOf('tab-basic','linkType');
        var selectedText = editor.getSelection().getSelectedText();

        if(componentType != ''){

            editor.insertText('[[' + componentType + ']]');

        }
    }
};
});

I actually copied this from another plug-in and modified it to suit, so I'll admit I don't much know what I'm doing here. I've dug through the CKEditor docs but they aren't particularly helpful.

The variable componentType is coming back with the file size. I'm just not sure how to make it grab the text instead of the value; if you view the source, the has the value of the file size, and the text is the filename.

Any ideas? Thank you!