Change current page query string with jquery.

querystring.js

function getQueryVariable(url, variable) {
  	 var queryString = url.substring(1);
     var index = queryString.indexOf("?");
     var vars = queryString.substr(index+1).split('&');
     for (var i=0; i<vars.length; i++) {
          var pair = vars[i].split('=');
          if (pair[0] == variable) {
            return pair[1];
          }
     }
     return false;
  }

function newUrl(FLD,VAL) {
  var currentUrl = window.location.href;
  var currentVal = getQueryVariable(currentUrl,FLD);
  return location.href.replace(FLD+"="+currentVal, FLD+"="+VAL);
}

// call funcitons with pages query string
newUrl('page','4')