Form To Text File Or FTP Command

I need to upload a file from a known location on a server to a static FTP address. Now I was using Windows built in FPT client which is easy and I can create a text file which contains the FTP commands i.e open 10.10.10.10 put file1

for example, The problem is the name of the file to be uploaded changes and the ftp script is simply a DOS text file. I need to therefore ask the user for the name to the file to upload and then using this together with the FTP command (as all other infomation stays the same) to upload the file. I was thinking about creating a simple web page asking them to put the name of the file into the form hot go. It would be good if the JavaScript could then take the input from the from as the file name and then FTP this (from the source directory which always stays the same) to the destination which also always stays the same.