头像上传问题（急急急）

我上传的时候  老是出错。求大侠救命啊。$generate.click(function() {
                    var me = $(this);                    me.fadeOut();
                    $opts.fadeOut();
                    $cutter.fadeOut();
                    $info.hide();
                    $processed.fadeIn();                    $.ajax({
                        url: 'scissors.axd',
                        dataType: 'json',
                        data: {
                            action: 'GenerateBitmap',
                            src: ps.src,
                            zoom: $bcglobal.$zoomValue,
                            x: $thumbimg.f('left'),
                            y: $thumbimg.f('top'),
                            width: ps.cutterSize.width,
                            height: ps.cutterSize.height,
                            t: Math.random()
                        },
                        error: function(err) {
                            alert('cant generate it!');
                        },
                        success: function(json) {
                            if (json.msg == 'success') {
                                me.fadeIn();
                                $opts.fadeIn();
                                $cutter.fadeIn();
                                $info.show();
                                $processed.fadeOut();
                                $newimg.attr('src', json.src).show();
                                ps.onGenerated(json.src);
                            }
                            else {
                                alert(json.msg);
                            }
                        }
                    });
                });
                $bcglobal.$cutter = $cutter;
                $bcglobal.$img = $img;
                $bcglobal.$thumbimg = $thumbimg;
            });
        }
    });