File upload control filepath disappeared after adding new row in table.

hi,
    I have a dynamic html table. I can create new rows by clicking 'add' button at runtime.
    Each row has 3 textboxes and a fileupload control. A row can be submitted after filling the textboxes and browsing the file for upload.
    A 'submit' button is there to submit a row(which will also upload the selected file).
    If i select a row, fill it, choose a file to upload after browsing and click submit button, it works fine.
   The problem is that if I fill a row (and not submit) and 'add' a new row, my previously selected file (filepath) disappears.
   What can I do to keep the file path remain after adding new rows?



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