Hello All , 

I need to do some major customization to the point of sale module , just the xml receipt . What i want to do is add an extra line called property company , which will automatically add data based on a sql query .

Now from what i can see the POS is powered by javascript , The questions i want to ask is :

1. What py file in the point_of_sale module can i add my new field and sql query(function) .

2. how does javascript files work and how can i go about displaying my new field 

Can any one guide me on this ?