need to get forms in separate browser windows to talk

I need to A.) have a form spawn a new window B.) be able to select an option from that window's form, and C.) populate input fields on the initial form based on the option selected. Parts A and B are done, but I'm having difficulty populating the initial form. Can't seem to be able to fully describe/see the field, i.e. document.reqName.value='Tom' , from the child form. I've done this with a frameset, but not from two separate windows.

Any help???

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