[CentOS] http form automation tools?

I need to grab some data from a remote web server that offers a csv 
download but only after viewing a chart where you have to first navigate 
to a form and make some selections.  Are there any good tools for 
automating this kind of access?  (What I'm really after are bandwidth 
stats from some routers where I only have read access to a CA/ehealth 
system that monitors it).  Previously the intermediate system was cacti 
where the link to the data download for a time interval can be computed 
directly.

-- 
   Les Mikesell
    lesmikesell at gmail.com