Set a value in the opener window doesn't really set it?

[Danny & Noemi Shafir]

Hey all,

I have a button that popup another little window with some information
to choose.
When you choose something in the popup window, it set the selected
value on the opener window with this command:

opener.document.formName.fieldName.value = selectedValue ;

BUT, I also have an onBlur event on that field (the one I set its
value).
and even I see that the value is in the field (on the screen), , when
activate the event and check the field's value, it seems
that the document doesn't "know" it has any value at all in this field.

Thanks to all,

Danny