// asAtDate must be a string of type yyyymmdd
	// function returns price, or -1 if out of range
	function getHistoricalPrice(asAtDate)
	{
		var count = wlOSHDateArr.length;
		var date = parseInt(asAtDate);
		if (date > wlOSHDateArr[count-1] || date < wlOSHDateArr[0])
			return -1;

		var lower = 0;
		var upper = count-1;
		var index = parseInt(upper/2);
		var curDate;

		// binary search for date
		while(upper - lower > 1)
		{
			curDate = wlOSHDateArr[index];
			if (curDate == date)
				return wlOSHPriceArr[index];
			if (curDate > date)
				upper = index;
			else
				lower = index;
			index = parseInt((upper+lower)/2);
		}
		// Make sure that what we've found is actually the right day.
		if (wlOSHDateArr[upper] == date) {
			return wlOSHPriceArr[upper];
		} else {
			return -1;
		}
	}
	
	function showHistoricalPrice()
	{
		var f = document.forms.HistoricalDataForm;
		var d = ("00" + f.day.value).slice(-2);
		var monthname = f.month.value;
		var y = ("0000" + f.year.value).slice(-4);
		var m = getMonth(monthname);
		if (isNaN(parseInt(d)) || isNaN(parseInt(m)) || isNaN(parseInt(y)))
		{
			alert("Please enter a date in dd/mm/yyyy format");
			return;
		}
		var price = parseFloat(getHistoricalPrice(y + m + d));
		if (price.toFixed != null)
		{
			price = price.toFixed(2);
		}
		//var msg = "On " + d + "/" + m + "/" + y + " the price was $" + price;
		var msg = "$" + price;
		if (price > -1)
		{
			document.getElementById("result").innerHTML = msg;
		}
		else
		{
		   document.getElementById("result").innerHTML = "<font color=red>no price info</font>"; 
		}
	}
	
	function getMonth(n)
	{
	    switch(n)
	    {
	        case "Jan":
	            return "01";
	            break;
	        case "Feb":
	            return "02";
	            break;
	        case "Mar":
	            return "03";
	            break;
	        case "Apr":
	            return "04";
	            break;
	        case "May":
	            return "05";
	            break;
	        case "Jun":
	            return "06";
	            break;
	        case "Jul":
	            return "07";
	            break;
	        case "Aug":
	            return "08";
	            break;
	        case "Sep":
	            return "09";
	            break;
	        case "Oct":
	            return "10";
	            break;
	        case "Nov":
	            return "11";
	            break;
	        case "Dec":
	            return "12";
	            break;
	    }
	}

    function RenderForm()
	{
	    document.write("<form action='test.asp' method='post' onsubmit='return false;' name='HistoricalDataForm'>");
	    document.write("<p>Show the closing price on");
	    document.write("<input type='text' size='2' id='day' name='day' value='03' />");
	    document.write("/<input type='text' size='2' id='month' name='month' value='01' />");
	    document.write("/<input type='text' size='4' name='year' id='year' value='2006' /> :");
	    document.write("<input type='button' id='Show' name='Show' value='Show' onclick='showHistoricalPrice();' />");
	    document.write("</p>");
        document.write("</form>");
	}