<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=Unicode" />
  <title>Calculator</title>
  <style type="text/css">
    body { width: 130; height: 67; margin: 0; }
    div { margin-top: 5; text-align: center; }
    span { color: Navy; font-family: Arial; font-size: 11; font-weight: bold; }
    input { font-size: 15; text-align:right; }
  </style>

  <script type="text/javascript">
    System.Gadget.settingsUI = "calculatorsettings.html";
    System.Gadget.onUndock = ResizeGadget;
    System.Gadget.onDock = ResizeGadget;
	
	stack = new Array();
	level = 0;
	
	function KeyPressHandler(e)
	{
	  var key = e.keyCode || e.which;
	  
	  if (key == 13)
	  { 
	    stack.push(calc.value);
	    level = stack.length;
	    calc.value = eval(calc.value);
	    ToFixed();
		}
	}

	function ToFixed() 
	{
	  if (fixed.checked && Number(calc.value) != NaN)
	    calc.value = Number(calc.value).toFixed(2);
	}
	
  function KeyDownHandler(e)
  {
    if (e.keyCode == 38)
    {
      level = Math.max(0, --level);
      calc.value = stack[level];
    }

    else if (e.keyCode == 40)
    {
      level = Math.min(stack.length - 1, ++level);
      calc.value = stack[level];
    }
  }
  
  function ResizeGadget()
  {
   if (System.Gadget.docked == true)
    {
        System.Gadget.background = "background.png";
        document.body.style.width = 130;
        calc.style.width = 100;
    }
    else
    {
        System.Gadget.background = "background2.png";
        document.body.style.width = 260;    
        calc.style.width = 230;
    }  
  }
  pi = Math.PI;
  rad = 57.2957795;
  
  function d2h(d) {return "0x" + d.toString(16);}
  function h2d(h) {return parseInt(h,16);} 
  
  function abs(x)   { return Math.abs(x); }
  function exp(x)   { return Math.exp(x); }
  function log(x)   { return Math.log(x); }
  function pow(x,y) { return Math.pow(x,y); }
  function sqrt(x)  { return Math.sqrt(x); }

  function cos(x)   { return Math.cos(x); }
  function sin(x)   { return Math.sin(x); }
  function tan(x)   { return Math.tan(x); }	

  function acos(x)  { return Math.acos(x); }
  function asin(x)  { return Math.asin(x); }
  function atan(x)  { return Math.atan(x); }	
 
  function rad2deg(x) { return  rad * x; }
  function deg2rad(x) { return 0.0174532925 * x; }

  function payment(principal, months, apr)
  {
   rate = apr / 12;
   monthly = principal * rate / (1 - (1 / Math.pow(1 + rate, months)));
   return monthly.toFixed(2);
  }

  </script>

</head>
<body onload="ResizeGadget()">
  <div>
    <span>Calculator</span>&nbsp;&nbsp;&nbsp;&nbsp;$<input type="checkbox" id="fixed" checked="checked" onclick="ToFixed()" />
    <input id="calc" type="text" onkeypress="KeyPressHandler(event)" onkeydown="KeyDownHandler(event)" />
  </div>
</body>
</html>