My website has a div element (in form of a block) that I want to make invisible whenever a user visits the website through a text based browser like Lynx, that doesn't support JavaScript.
Basically what command or code do I need to write in order for this to happen?
Since you can't run javascript there, you have to not send that div in the first place for it to be invisible in the text-mode browser.
You can make a server side user-agent check and do not render that div. Lynx user agents: http://www.useragentstring.com/pages/Lynx/