Giving equal page numbers such as InDesign

/**
* Set sections for spread numbering 
* @ return Void 
* 
*/
function spreadNumbers(){
    var d = app.activeDocument;
    var sp = d.spreads.everyItem().getElements();
    var ds = d.documentPreferences.allowPageShuffle
    d.documentPreferences.allowPageShuffle = false;
    
    //Clear any existing sections;
    var s = app.activeDocument.sections;
    if (s.length > 1) {
        s.itemByRange(1,s.length-1).remove();
    } 
    var sn;
    for (var i = 0; i < sp.length; i++){
        sn = i+1;
        try {
            d.sections.add({continueNumbering:false, pageStart:sp[i].pages.lastItem(), pageNumberStart:sn})
        }catch(e) {} 
    };  
    d.documentPreferences.allowPageShuffle = ds;
}


app.doScript(spreadNumbers, ScriptLanguage.JAVASCRIPT, undefined, UndoModes.ENTIRE_SCRIPT, 'Spread Numbers');