Programming and Scripting :: programming about download progress ?

the system is :DSL 2.2
the programming goal is download a file through http server.
tools: FLUA
i create a simple window dialog using FLUA script.
it contain a input (the address of url) and a download button .
when i enter the download button ,the script execute the wget ...... to download the file.
we want to display the download progress in the dialog. (running this script in xterm ,we get the progress.but we don't adopt the method )
"wget .... &2>progress" can record the download process in file progress in special file format.
our main idea is when the program executes the wget in background. we start another thread to read the file progress,retrive the XX% and display it in the dialog interval. we use the BOX's label to display the X%.
But we don't know how to implment it ?

any suggestion is appreciate.

original here.