How to use Pagination using script

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Hi Team ,

Am using below script to get the pagination 

var limit = 3;
var offset = 1;

var gr = new GlideRecord('incident');

gr.addQuery('short_description','test');
gr.orderByDesc("number");
gr.setLimit(limit);
gr.setOffset(offset);
gr.query();

while (gr.next()) {
var fieldValue = gr.getValue('number');
gs.info(fieldValue);
}

Note:setLimit is working but setOffset syntax is not working

am getting the same values (number) after changing Offset 

Please guide me