How do I extract the file name of an uploaded file in Deluge script?

How do I extract the file name of an uploaded file in Deluge script?

If I just do the following

sampleForm.UploadField

I get the a long number followed by the file name (eg. 12123243434_ThisIsTheFileName.pdf)

But I just want to get: ThisIsTheFileName.pdf

I could cut off the number part in script. But the next time the behavior of the Upload Field in Zoho Creator is changed (like it recently has) I would have to adjust it again...

Thanks, Filip