windows open  focus has      event
============  =============  ===== 
index.html    index.html     user clicks "register now"
                             open new Window f1

index.html    newWindow f1   user fills out the form
newWindow f1                 and submits (newWindow closes)

index.html    index.html     open new Window f2

index.html    newWindow f2   user fills out the form
newWindow f2                 and submits (newWindow closes)
                                 
index.html    index.html