Prevent a duplicate page submit in oracle apex

1. Prevent duplicate page  using java-scripts
2. Prevent duplicate page using button disabled
3. Prevent duplicate page using page setting no

• Before Page Submit
• Execute java scripts code

$("body").append('<div class="ui-widget-overlay ui-front"/>');
apex.widget.waitPopup();
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$("body").append('<div class="ui-widget-overlay ui-front"/>'); apex.widget.waitPopup();