大神在哪？帮忙看下程序，哪出问题了？不能自动刷新............小妹在此谢过！
var WINDOW_WIDTH = 1024;
var WINDOW_HEIGHT = 768;
var RADIUS = 8;
var MARGIN_TOP = 60;
var MARGIN_LEFT = 30;
//endTime为截止的时间；小时为两位数，所以最多就倒计时四天，（从现在到截止时间为止）；月份要+1,5是代表6月份；
//从现在到2015年6月15日倒计时
const endTime=new Date(2015,5,15,18,47,52);
var curShowTimeSeconds=0;
window.onload = function(){
var canvas = document.getElementById('canvas');
var context = canvas.getContext("2d");
//计算现在的时间
curShowTimeSeconds=GetCurrentShowTimeSeconds();
canvas.width = WINDOW_WIDTH;
canvas.height = WINDOW_HEIGHT;
setInterval(
//匿名函数。每帧的执行内容
function()
{
render(context);
update();
},
//时间，单位：毫秒；50表示每隔多少毫秒执行一帧
50
);
}
function update()
{
var nextShowTimeSeconds = getCurrentShowTimeSeconds();
var nextHours = parseInt(nextShowTimeSeconds/ 3600);
var nextMinutes = parseInt((nextShowTimeSeconds - nextHours*3600) / 60);
var nextSeconds = nextShowTimeSeconds % 60;
var curHours =parseInt(curShowTimeSeconds/3600);
var curMinutes = parseInt((curShowTimeSeconds-hours*3600)/60);
var curSeconds =curShowTimeSeconds%60;
if(nextSeconds != curSeconds){
curShowTimeSeconds = nextShowTimeSeconds;
}
}
function render( cxt ){
//对整个屏幕进行刷新
cxt.clearRect(0,0,WINDOW_WIDTH,WINDOW_HEIGHT);
var hours =parseInt(curShowTimeSeconds/3600);
var minutes = parseInt((curShowTimeSeconds-hours*3600)/60);
var seconds =curShowTimeSeconds%60;
//数字是7*10的矩阵，冒号是4*10的矩阵
renderDigit( MARGIN_LEFT , MARGIN_TOP , parseInt(hours/10) , cxt )
renderDigit( MARGIN_LEFT + 15*(RADIUS+1) , MARGIN_TOP , parseInt(hours%10) , cxt )
renderDigit( MARGIN_LEFT + 30*(RADIUS + 1) , MARGIN_TOP , 10 , cxt )
renderDigit( MARGIN_LEFT + 39*(RADIUS+1) , MARGIN_TOP , parseInt(minutes/10) , cxt);
renderDigit( MARGIN_LEFT + 54*(RADIUS+1) , MARGIN_TOP , parseInt(minutes%10) , cxt);
renderDigit( MARGIN_LEFT + 69*(RADIUS+1) , MARGIN_TOP , 10 , cxt);
renderDigit( MARGIN_LEFT + 78*(RADIUS+1) , MARGIN_TOP , parseInt(seconds/10) , cxt);
renderDigit( MARGIN_LEFT + 93*(RADIUS+1) , MARGIN_TOP , parseInt(seconds%10) , cxt);
}
function GetCurrentShowTimeSeconds()
{
var curTime=new Date();
//截止的时间距现在的秒数
var ret=endTime.getTime()-curTime.getTime();
//把ret转化为毫秒数，现在距设定的endTime的的时间
ret=Math.round(ret/1000);
return ret>0?ret:0;
}
function renderDigit( x , y , num , cxt ){
cxt.fillStyle = "rgb(0,102,153)";
for( var i = 0 ; i < digit[num].length ; i ++ )
for(var j = 0 ; j < digit[num][i].length ; j ++ )
if( digit[num][i][j] == 1 ){
cxt.beginPath();
cxt.arc( x+j*2*(RADIUS+1)+(RADIUS+1) , y+i*2*(RADIUS+1)+(RADIUS+1) , RADIUS , 0 , 2*Math.PI )
cxt.closePath()
cxt.fill()
}
}
