如下代码：

//直线  1
            {
            cxt.strokeStyle = "#FF0000";
            cxt.moveTo(x1,80-b);            
            x1=x1+1.63;
            b=b+b1;         
            cxt.lineTo(x1,80-b); 
            cxt.stroke();}

            //直线  2
            {
            cxt.strokeStyle = "#008000";
            cxt.moveTo(x2,80-c);            
            x2=x2+1.63;
            c=c+c1;     
            cxt.lineTo(x2,80-c); 
            cxt.stroke();}

            //直线  3
            {
            cxt.strokeStyle = "#0000F5";
            cxt.moveTo(x3,80-d);            
            x3=x3+1.63;
            d=d+d1;     
            cxt.lineTo(x3,80-d);                
            cxt.stroke();}     

为什么画出来的直线都是最后设置的一个颜色，如何画出不同的颜色呢？谢谢