取当前时间，格式为,yyyy-mm-dd hh:mm:ss

function CurentTime()
    { 
        var now = new Date();
        
        var year = now.getFullYear();       //年
        var month = now.getMonth() + 1;     //月
        var day = now.getDate();            //日
        
        var hh = now.getHours();            //时
        var mm = now.getMinutes();          //分
        var ss = now.getSeconds();           //秒
        
        var clock = year + "-";
        
        if(month < 10)
            clock += "0";
        
        clock += month + "-";
        
        if(day < 10)
            clock += "0";
            
        clock += day + " ";
        
        if(hh < 10)
            clock += "0";
            
        clock += hh + ":";
        if (mm < 10) clock += '0'; 
        clock += mm + ":"; 
         
        if (ss < 10) clock += '0'; 
        clock += ss; 
        return(clock); 
}

 alert(CurentTime())就可以了