[ruslan_mart]

$(function() {
    var content = $('#content');

    content.on('click', 'a[href][id!="noajax"]', function() {
         var url = this.href + (this.search.length > 1 ? '&' : '?') + 'ajax=1';
         content.load(this.href + ' #content');
         window.history.pushState(null, null, url);
         return false;
    });

    window.addEventListener('popstate', function() {
        content.load(this.location.href + ' #content');
    });
});