ip.showFlame=false;
            }, false);
            (function drawFrame(){
                window.requestAnimationFrame(drawFrame,canvas);
                context.clearRect(0,0,cw,ch);
                ship.rotation+=vr*Math.PI/180;
                var angle=ship.rotation,
                    ax=Math.cos(angle)*thrust,
                    ay=Math.sin(angle)*thrust;
                vx+=ax;
                vy+=ay;
                ship.x+=vx;
                ship.y+=vy;
                if(ship.x>cw||ship.x<0