Sales Order Customer Discount Update Upon Customer Select

Goal; to load up Customer Discount into Sales Order from Customer file.
This is my code.  I cannot get this to work which is unknown to me why?

function postSourcing(type, name)
{
// When customer is selected get customer discount code from
//      CUSTOMER file and put into SALES ORDER entry screen
// Goal: move value of custentity_altp_cust_dscnt ----> discountitem
// In ITEM file, Discount Item Numbers were created.
// In CUSTOMER file, Customer ID field is;             entity
// In CUSTOMER file, Customer Discount field is;             custentity_altp_cust_dscnt ---+
// In SALES ORDER entry, Customer field ID is;   entityid                               |
// In SALES ORDER entry, Discount Item field ID is; discountitem   <--------------+