(function($){
  $.fn.extend({
    spin: function(opt){
      return this.each(function(){
        opt = $.extend({
            imageBasePath: '../app_images/',
            spinBtnImage: 'spin-button.gif',
            spinUpImage: 'spin-up.gif',
            spinDownImage: 'spin-down.gif',
            interval: 1,
            max: null,
            min: null,
            timeInterval: 500,
            timeBlink: 200
          }, opt || {});
        
        var txt = $(this);
        
        var spinBtnImage = opt.imageBasePath+opt.spinBtnImage;
        var btnSpin = new Image();
        btnSpin.src = spinBtnImage;
        var spinUpImage = opt.imageBasePath+opt.spinUpImage;
        var btnSpinUp = new Image();
        btnSpinUp.src = spinUpImage;
        var spinDownImage = opt.imageBasePath+opt.spinDownImage;
        var btnSpinDown = new Image();
        btnSpinDown.src = spinDownImage;
        
        var btn = $(document.createElement('img'));
        btn.attr('src', spinBtnImage);
        btn.css({ cursor:'pointer', verticalAlign:'top', padding:0, margin:0, display:'inline' });
		if ($.browser.msie) btn.css({ paddingTop:2 }); else if ($.browser.safari) btn.css({ paddingTop:3 });
        txt.after(btn);
        txt.css({marginRight:0, paddingRight:0});
        
        function spin(vector){
          var val = txt.val();
          if(!isNaN(val)){
            val = parseFloat(val) + (vector*opt.interval);
            if(opt.min!=null && val<opt.min) val=opt.min;
            if(opt.min!=null && val>opt.max) val=opt.max;
            if(val != txt.val()){
              txt.val(val);
              txt.change();
              src = (vector > 0 ? spinUpImage : spinDownImage);
              btn.attr('src', src);
              if(opt.timeBlink<opt.timeInterval)
                setTimeout(function(){btn.attr('src', spinBtnImage);}, opt.timeBlink);
            }
          }
        }
        
        btn.mousedown(function(e){
          var pos = e.pageY - btn.offset().top;
          var vector = (btn.height()/2 > pos ? 1 : -1);
          (function(){
            spin(vector);
            var tk = setTimeout(arguments.callee, opt.timeInterval);
            $(document).one('mouseup', function(){
              clearTimeout(tk); btn.attr('src', spinBtnImage);
            });
          })();
          return false;
        });
      });
    }
  });
})(jQuery);