reading & writing sqlite database with javascript

I am currently trying to get my head around database's and web programming. I currently have 3 files index.html, script.js (empty at the minute) and test_db.sqlite. I am trying to pull info from the sqlite database, create a javascript variable with the info and the print it to the html with the document.getElementById method.

What I'd having trouble with is reading the database using javascript. I am willing to use jquery or any other extra JS scripts, but I cannot use php as I intend to use this to create a cross platform app with a python web wrapper on windows & linux and phonegap for iOS and Android.

I also need to figure out to write to the database with javascript.

Thank you for any help in advance.