CODE EXAMPLE FOR JAVASCRIPT

Ajax wait until success

$(".my_link").click(
    function(){
    $.ajax({
        url: $(this).attr('href'),
        type: 'GET',
        async: false,
        cache: false,
        timeout: 30000,
        fail: function(){
            return true;
        },
        done: function(msg){ 
            if (parseFloat(msg)){
                return false;
            } else {
                return true;
            }
        }
    });
});