Additional information, This is what I do on pageA before clicking "Item Group"

$mech->submit_form(
        form_name => 'eventmaintenance',
        fields    => {
        EventName => 'test',
        EventDesc => 'test',        EventCategory => 'Option2', }
    );

$mech->submit_form(
        form_name => 'eventmaintenance',
        fields    => {
        bDoNotNotify => 'true',
        EventTypeCode => 'Option2',
        bDoNotNotify => 'true',                  BeginDateYYYY => '200
+5',
        BeginDateMM => 'Aug',
        BeginDateDD => '4',
        EndDateYYYY => '2005',
        EndDateMM => 'Aug',
        EndDateDD => '7',
} 
    );
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