Width of the image represented by the specified item of the upload list.
value = getImageUploader("ImageUploaderID").getUploadFileWidth(Index);
A positive integer which specifies an index of the upload list item (i.e. the upload file). An index is 1-based. In other words valid value is in range [1, UploadFileCount].
A non-negative integer value that specifies width of the specified item of the upload list. If an item represents non-image,
0 is returned.