Hello,I'm a green hand in using HighChats.
In my project,through setting categories,to emerge the title of XAixs.But the categories are to long,when set the rotation for -90,the charts overlap the categories.
Please tell me how to solve the problem,thank you.

the code as follows

        chart = new Highcharts.Chart({
            chart: {
                renderTo: 'container', //图表容器Id
                defaultSeriesType: 'spline', //图表类型 line, spline, area, areaspline, column, bar, pie , column，scatter
                inverted: false,  //左右显示，默认上下正向。假如设置为true，则横纵坐标调换位置
                plotBackgroundColor: null,
                plotBorderWidth: null,
                zoomType: 'y',
                spacingRight: 2,  //图表距右侧的位置
                spacingLeft: 2,  //图表距右侧的位置
                plotShadow: false
            },

            title: {
                text: "测试图表标题" //图表标题
            },

            //Y轴坐标标题  labels:纵柱标尺 
            yAxis: {
                min: -10,
                max: 10,
                title: {
                    enabled: false,
                    text: ''
                },

                labels: {
                    formatter: function() {
                        if (this.value == "" || this.value == null) {
                            return '0';
                        }
                        if (parseInt(this.value) == 0) {
                            return '1';
                        }
                        if (parseInt(this.value) > 0) {
                            return '1E+' + this.value;
                        }
                        if (parseInt(this.value) < 0) {
                            return '1E' + this.value;
                        }
                    }
                }
            },

            xAxis: {
                allowDecimals: false, //间隔不出现小数
                gridLineWidth: 1,
                categories: ['1Q/2008','2Q/2008','3Q/2008','4Q/2008','1Q/2009','2Q/2009','3Q/2009','4Q/2009','1Q/2010','2Q/2010','2Q/2011','3Q/2011'],

                labels: {
                    rotation: -90,        //坐标值显示的倾斜度
                    formatter: function() {
                        return this.value;
                    }
                }
            },

            //当鼠标悬置数据点时的格式化提示     
            tooltip: {
                formatter: function() {
                    return '<b>' + this.series.name + '</b>:<br/>' + this.point.xTtile + '; ' + this.point.name;
                }
            },
            series: [{
                type: "line", //图表类型
                name: "测试图表名称", //图表名称
                data: [{name:'2.71E-06',xTtile:'1Q/2008',y:-5.56},{name:'2.71E-10',xTtile:'2Q/2008',y:-10},{name:'1E-03',xTtile:'3Q/2008',y:-3},{name:'2.78E-06',xTtile:'3Q/2009',y:-5.55615484484342},{name:'5.07E-10',xTtile:'4Q/2009',y:-9.29462379898524},{name:'4.72E-09',xTtile:'1Q/2010',y:-8.32581892918103},{name:'-6.95E-08',xTtile:'2Q/2010',y:-7.15820447353134},{name:'3.22E-06',xTtile:'2Q/2011',y:-5.49256070748956},{name:'-2.61E-07',xTtile:'3Q/2011',y:-6.5829935748812}]

}]

            });