if _txt.text not working?

[objuan]

I have a bunch of pictures, each one on a frame in an MC. Bellow each photo is a dynamic text box named PhotoComments_txt, with various comments typed into it on each frame. Many say:
"Type comments here. If no comments leave this text."

I have this code on a button over the photos, the idea being to pass along the comment, or skip it if their isn't one:

on(rollOver){
    if(PhotoComments_txt.text != "Type comments here.  If no comments leave this text."){
        _level0.Comment_txt.text = PhotoComments_txt.text + " - Click to enlarge photo";
    } else {
        _level0.Comment_txt.text = "Click to enlarge photo";
    }
}

It doesnt work? Not only that, what it does do doesnt make any sense. Do-ed it?
It passes along the comment regardless of what it is, and it never ads nor changes it to "Click to enlarge photo" Even if the PhotoComments_txt is "Type comments here. If no comments leave this text." then it passes that along, which to my line of reasoning should give Flash no reason to change _level0.Comment_txt.text to PhotoComments_txt.text

yarghh?