// pop-up window function

function popWin(page) {
	window.open(page, "helpWin", "width=400,height=350,scrollbars=yes,status=yes,resizable=yes");
}

// create expiration date for 30 days

var thirtydays = new Date();
var expDate = thirtydays.getTime() + (60 * 60 * 24 * 30 * 1000);
thirtydays.setTime(expDate);


// set date for immediate expiration 
var expireNow = new Date();


// get the value of the specified cookie (name)

function readCookie(name) {
    var start = document.cookie.indexOf(name+"=");
    var len = start+name.length+1;
    if ((!start) && (name != document.cookie.substring(0,name.length))) return null;
    if (start == -1) return null;
    var end = document.cookie.indexOf(";",len);
    if (end == -1) end = document.cookie.length;  //begin modification
    var string_value = unescape(document.cookie.substring(len,end));
	var numeric_value = parseInt(string_value);
	return numeric_value;
 }


// read the value of the quantity of each video (from cookies)


var vid1_qty = readCookie("vid1");
var vid2_qty = readCookie("vid2");
var vid3_qty = readCookie("vid3");
var vid4_qty = readCookie("vid4");


// calculates subtotal for each video based on value retireved from cookie

function subTotal(qty) {
	var item_price = 24.95;
	return item_price * qty;
}

// calculates grand total by adding subtotals

function endTotal(a,b,c,d) {
	return a + b + c + d;
}

// assigns values to subtotal variables

var vid1_subtotal = subTotal(vid1_qty);
var vid2_subtotal = subTotal(vid2_qty);
var vid3_subtotal = subTotal(vid3_qty);
var vid4_subtotal = subTotal(vid4_qty);

var grandTotal = endTotal(vid1_subtotal,vid2_subtotal,vid3_subtotal,vid4_subtotal);


// fixes problem with improper decimal points on subtotals

function fixNumString(number) {  // input the number (subtotal, total) in string form, returnd string with decimal 0's
	var oldString = number.toString();
	var result = oldString.match(/\.+\d+\d/);

	if(result == null) {
		var fixedNumber = oldString + "0";
	}
	else {
		var fixedNumber = oldString;
	}
	// begin IE long decimal bug fix
	var number_end = oldString.indexOf(".") + 3;
	var fixed = fixedNumber.substring(0,number_end);

	return fixed;
}


// function that builds the cart HTML

function makeCart() {  

	// if cart is empty, display text only

	if(((vid1_qty == null) || (vid1_qty == 0)) && ((vid2_qty == null) || (vid2_qty == 0)) && ((vid3_qty == null) || (vid3_qty == 0)) && ((vid4_qty == null) || (vid4_qty == 0))) {

		var help_page = "'help_cookies.html'";
		document.write('<font face="Verdana,Arial,Helvetica">Your shopping cart currently contains no items.</font>');
		document.write('<p><font face="Verdana,Arial,Helvetica" size="2">If you have added an item to the cart, and receive this message, you may not have &quot;cookies&quot; enabled on your web browser. </font>');
		document.write('<a href="javascript:popWin(' + help_page + ')"><font face="Verdana,Arial,Helvetica" color="#ffcc66" size="2">Click here for help with &quot;cookies.&quot;</font></a>');

	}

	else {  // write HTML for the FORM

		document.write('<font face="Verdana,Arial,Helvetica">');
		document.write('<form name="CartForm" method="post">');

		document.write('<table border="1" cellpadding="2" cellspacing="0" width="390">');
		document.write('<tr>');
		document.write('<td width="18%" bgcolor="#ffcc66" align="center">');
		document.write('<font face="Verdana,Arial,Helvetica" color="black" size="2"><b>Quantity</b></font></td>');
		document.write('<td bgcolor="#ffcc66" align="center">');
		document.write('<font face="Verdana,Arial,Helvetica" color="black" size="2"><b>Item</b></font></td>');
		document.write('<td width="18%" bgcolor="#ffcc66" align="center">');
		document.write('<font face="Verdana,Arial,Helvetica" color="black" size="2"><b>Subtotal</b></font></td>');
		document.write('</tr>');

		// item specific data

			// video1

		if((vid1_qty != null) && (vid1_qty != 0)) {
			document.write('<tr>');
			document.write('<td width="18%" align="center">');
			document.write('<input type="text" name="vid1_qty_txt" size="3" maxlength="3" value=' + vid1_qty + '></td>');
			document.write('<td align="left">');
			document.write('<font face="Verdana,Arial,Helvetica" size="2">Video # 1 - Intro to Qi Gong</font></td>');
			document.write('<td width="18%" align="right">');
			document.write('<font face="Verdana,Arial,Helvetica" size="2">$' + fixNumString(vid1_subtotal) + '</font></td>')  /
			document.write('</tr>');
		}

			// video2

		if((vid2_qty != null) && (vid2_qty != 0)) {
			document.write('<tr>');
			document.write('<td width="18%" align="center">');
			document.write('<input type="text" name="vid2_qty_txt" size="3" maxlength="3" value=' + vid2_qty + '></td>');
			document.write('<td align="left">');
			document.write('<font face="Verdana,Arial,Helvetica" size="2">Video # 2 - Intro to Nei Gong</font></td>');
			document.write('<td width="18%" align="right">');
			document.write('<font face="Verdana,Arial,Helvetica" size="2">$' + fixNumString(vid2_subtotal) + '</font></td>')  /
			document.write('</tr>');
		}

			// video3

		if((vid3_qty != null) && (vid3_qty != 0)) {
			document.write('<tr>');
			document.write('<td width="18%" align="center">');
			document.write('<input type="text" name="vid3_qty_txt" size="3" maxlength="3" value=' + vid3_qty + '></td>');
			document.write('<td align="left">');
			document.write('<font face="Verdana,Arial,Helvetica" size="2">Video # 3 - 10 Minute Sessions</font></td>');
			document.write('<td width="18%" align="right">');
			document.write('<font face="Verdana,Arial,Helvetica" size="2">$' + fixNumString(vid3_subtotal) + '</font></td>')  /
			document.write('</tr>');
		}

			// video4

		if((vid4_qty != null) && (vid4_qty != 0)) {
			document.write('<tr>');
			document.write('<td width="18%" align="center">');
			document.write('<input type="text" name="vid4_qty_txt" size="3" maxlength="3" value=' + vid4_qty + '></td>');
			document.write('<td align="left">');
			document.write('<font face="Verdana,Arial,Helvetica" size="2">Video # 4 - 5 Minute Sessions</font></td>');
			document.write('<td width="18%" align="right">');
			document.write('<font face="Verdana,Arial,Helvetica" size="2">$' + fixNumString(vid4_subtotal) + '</font></td>')  /
			document.write('</tr>');
		}


		// closing data (end table and write submit button)
		document.write('<tr>');
		document.write('<td align="center" width="18%" bgcolor="#FFCC66"><font face="Verdana,Arial,Helvetica"><input type="button" value="Update" name="UpdateQty" onClick="updateCart()"></font></td>');
		document.write('<td bgcolor="#FFCC66" colspan="2"><font face="Verdana,Arial,Helvetica" size="2" color="black">Click &quot;Update&quot; when making changes in Quantity.</font></td>');
		document.write('</tr>');
		document.write('<tr><td width="18%" height="16"></td><td></td><td width="18%"></td></tr>'); // empty row
		document.write('<tr>');
		document.write('<td bgcolor="#ffffff" colspan="2" align="left">');
		document.write('<font face="Verdana,Arial,Helvetica" color="black" size="2"><b>Subtotal:</b></font></td>');
		document.write('<td bgcolor="#ffffff" width="18%" align="right">');
		document.write('<font face="Verdana,Arial,Helvetica" color="black" size="2"><b>$' + fixNumString(grandTotal) + '</b></font></td>'); 
		document.write('</tr>');
		document.write('</table>');
		document.write('<br><br>');
		document.write('<div align="right"><input type="button" value="Continue to Checkout &gt;&gt;" name="submitVerisign" onClick="goCheckout()"></div>');  // goCheckout() function resides in cart.html
		document.write('</form>');
		document.write('</font>');

	}
}

function updateCart() {

	// video # 1

	if((vid1_qty != null) && (vid1_qty != 0))  {
		if(document.CartForm.vid1_qty_txt.value == 0) {
			document.cookie = "vid1=0; expires=" + expireNow.toGMTString();
		}
		else 
			document.cookie = "vid1=" + document.CartForm.vid1_qty_txt.value + "; expires=" + thirtydays.toGMTString();

	}

	// video # 2

	if((vid2_qty != null) && (vid2_qty != 0))  {
		if(document.CartForm.vid2_qty_txt.value == 0) {
			document.cookie = "vid2=0; expires=" + expireNow.toGMTString();
		}
		else 
			document.cookie = "vid2=" + document.CartForm.vid2_qty_txt.value + "; expires=" + thirtydays.toGMTString();

	}

	// video # 3

	if((vid3_qty != null) && (vid3_qty != 0))  {
		if(document.CartForm.vid3_qty_txt.value == 0) {
			document.cookie = "vid3=0; expires=" + expireNow.toGMTString();
		}
		else 
			document.cookie = "vid3=" + document.CartForm.vid3_qty_txt.value + "; expires=" + thirtydays.toGMTString();

	}

	// video # 4

	if((vid4_qty != null) && (vid4_qty != 0))  {
		if(document.CartForm.vid4_qty_txt.value == 0) {
			document.cookie = "vid4=0; expires=" + expireNow.toGMTString();
		}
		else 
			document.cookie = "vid4=" + document.CartForm.vid4_qty_txt.value + "; expires=" + thirtydays.toGMTString();

	}

	location.reload();  // refresh the page
}