javascript - How can I add additional value to variable in jquery -

i trying add dates slider , need increment values on click. start year - 2

$('#adddates').click(function() {     var year = 2;     $("#slider").daterangeslider({         bounds: {             min: new date(today.getfullyear() - ++year, 0, 1),             max: new date(today.getfullyear(), today.getmonth(), today.getdate())         }     }); }); 

on click getting additional year. need increase number of year variable 2 on each click. how can achieved?

if you're asking how maintain year value declare outside of click event:

$( document ).ready(function() {     var year = 2; // abstracting year away click function     $('#adddates').click(function() {         $("#slider").daterangeslider({             bounds: {                 min: new date(today.getfullyear() - ++year, 0, 1),                 max: new date(today.getfullyear(), today.getmonth(), today.getdate())             }         });     }); }); 

please note however, if reason sort of server side post value reset.