I have a problem when i create service order.
here is the scenario :
1. i create a service order A and save A
2. i create a followup order for A , and named B, saved B
3. i create another followup order for A, and named C, but we don't save C now
4. on the page of C , there is a input field named input_field,
before saving C, we want to get a value from B , and put the value into input_field.
5. then we save order C.
problem is I don't know how to do the step 4
how to get the value and put it into the field on the page.