asp smartupload subscript out of range

you are using smart upload for uploading a file to the server and you get this ugly erro message "asp smartupload subscript out of range" and i'm sure that you didn't write the uploading script.. well, i spent one whole day with this error, and a got angry when i knew that it's a stupid mistake. just look at the html form the the data sent from, you shoud set the enctype to multipart/form-data

that's all!!