js prototype 格式化数字 By shawl.qiu

<%  
    var $num=9876577784321.011  
        Number.prototype.formatNumber=function(pointPsti){  
        /*--------------------------------------------------------*\    
         *    Javascript 格式化数字原型, By shawl.qiu  
         *    客户端使用: var $num=9876577784321.011; document.write('<br/>'+$num.formatNumber(3)+'<br/>');  
         *    服务端使用: var $num=9876577784321.011; Response.Write($num.formatNumber(3));   
        \*--------------------------------------------------------*/  
            if(this=='')return false;  
            if(typeof(pointPsti)=='undefined'){  
                var pointPsti=3;  
            } else { if(isNaN(pointPsti)){pointPsti=3}; }  
            var num=this+'', numDc='', temp='';  
            if(num.indexOf('.')>-1){ ptPs=num.indexOf('.'); numDc=num.substr(ptPs); num=num.substr(0,ptPs); }  
            for(var i=num.length-1; i>=0;temp+=num.substr(i,1), i--);  
            var re=new RegExp('(.{'+pointPsti+'})','g');  
                temp=temp.replace(re,'$1,'); num='';                  
            for(var i=temp.length-1; i>=0; num+=temp.substr(i,1), i--);  
                num=num.replace(/^\,|\,$/,'')+numDc;  
            return num; // shawl.qiu script  
        }  
            Response.Write($num.formatNumber(3)+'<br/>');  
%>