Passing i value to a onRollover funcion HELP!!!!

I am trying to make a row of buttons depending on how many a person wants using flash and xml. But for some reason the rollOver function isnt working and the thumbnail images are not being set. Can some one hep me please.

for (i=0;i<_root.ThumbnailsImages.length;){
var t = _root.LowerSection.Thumbnails.attachMovie("LowerSection_Thumbnail_Container", "LowerSection_Thumbnail_Container"+i, i);

t._x = t._width*i;

t.ThumbPic.contentPath=_root.ThumbnailsImages ;

t.Testimonial.text = caption;
var TestimonialColor:TextFormat = new TextFormat();
TestimonialColor.color = ColorCoding+_root.captionColor ;
t.Testimonial.setTextFormat(TestimonialColor);

t.Thumbnail_Button.onRollOver = function(i){
_root.LowerSection.Video_Info.ClickedTitle.text = _root.clickedtitle;
_root.LowerSection.Video_Info.ClickedCaption.text = _root.clickedcaption ;
}

i++;
}