Creating new child records in a window

[Wizard Systems]

I have a layout with a portal of child records. I want to create a button that will open a new window and start with a new record. I need to keep the parent record active such that the new child record will be related to the parent. When I set up the script to do that, the "new record" clears the parent also. I want to keep the parent record (obviously). What am I doing wrong?

Script:

New Window

Go to Field

New record / request

[RalphL]

You can set your relationship to allow creation of related records and make your related record in the portal.

Or

You can add a global field gSerial Number. then your script would be

Set Field [gSerial Number; Serial Number]

Go to layout [ Related record]

New record/request

Set field [ Parent Serial Number; gSerial Number]

go to layout [Parent]