Node.JS how to capture field value and send to server side using Jade

I have a Node.JS express app using Jade as my front end. I know how to pass variable from the backend to the front end, but how do I pass data back to server side. For example I have a grid that is populated from a database. When I add a new row in the front end, I need to pass it to the backend so that it can log it into the database.