    function draw()  
      {  
    var canvas = document.getElementById('circle');  
    if (canvas.getContext)  
    {  
    var ctx = canvas.getContext('2d');   
    var X = canvas.width / 2;  
    var Y = canvas.height / 2;  
    var R = 45;  
    ctx.beginPath();  
    ctx.arc(X, Y, R, 0, 2 * Math.PI, false);  
    ctx.lineWidth = 3;  
    ctx.strokeStyle = '#FF0000';  
    ctx.stroke();  
    }  
    }  