$("#start").click(function(){
        var request = $.ajax({
                          url: 'gd.php',
                          type: "GET",
                          data: {
                                dados
                          },
                          success: function(data) {
                            //data = $.parseJSON(data);
                            console.log(data);
                            $('#gera-img').html(data);
                          },
                          beforeSend: function(){
                            $('#start').css("display", "none");
                            $('.loader').css("display", "block");
                          },
                          complete: function(){
                            $('.loader').css("display", "none");
                          }
                        });

         });