I have two modules. 

Sales Order 

Job Order 

Both have a description. 

Both modules are linked. So the description of the Job Order should mimic that of its assigned Sales Order. When I create a Job Order, I want the description field to not be null but get and display the description of its assigned Sales Order

I was tweaking some code of other forums but can't get the right match. 

I have the list of API's that i need. I just need to be pointed in the right direction of how exactly to configure this function. 

API for Sales Orders: (Sales_Orders)