Saving data from a web form to a local file

I am trying to code (.net) in the autosave functionality without clogging the network. I am trying to capture data from a webpage into a file on the local drive and automate save every 5 mins. Then finally when the user hits "save" the data should be pulled from the local file to update the data base. This should help to 开发者_StackOverflow中文版auto save without clogging the network. Any other suggestions are welcome. regards SB

Obligatory HTML5 suggestion! Here we go..

Check out this post of HTML5 local storage and asp.net.