Send email from a comment box

[Kofotmh]

I designed a small website last year in visual web developer. I added a small facility using smtp class, basically it allows people to write comments in a text box and once clicked "send" it sends me an email of whatever they typed.I am now using cPanel, and there is no .net support from what I can see (I am not using a dedicated server, it's a linux shared hosting), how can I write something like this in such different technology? I dont want to touch my existing CMS as I already have my site fully designed its very simple and functional.I just need pointing to the right direction please.