function getXMLHttp() {
  var xmlHttp

  try
  {
    //Firefox, Opera 8.0+, Safari
    xmlHttp = new XMLHttpRequest();
  }
  catch(e)
  {
    //Internet Explorer
    try
    {
      xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch(e)
    {
      try
      {
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch(e)
      {
        alert("Your browser does not support AJAX!")
        return false;
      }
    }
  }
  return xmlHttp;
}

function MakeRequest() {
  var xmlHttp = getXMLHttp();
  
  xmlHttp.onreadystatechange = function()
  {
    if(xmlHttp.readyState == 4)
    {
      HandleResponse(xmlHttp.responseText);
    }
  }

  xmlHttp.open("GET", "http://www.psdgator.com/includes/get-coupon.php?c=" + document.getElementById('coupon').value, true); 
  xmlHttp.send(null);
}

function HandleResponse(response) {
	document.getElementById('discountvalue').value = response;
	
	if (response == '0') {
		document.getElementById('coupontext').innerHTML = 'coupon code is invalid';
	} else {
		document.getElementById('coupontext').innerHTML = response + '% discount included';
	}
	
	calc();
}

function calc() {

	var totalvalue = 0;

	// get package value
	for (var i=0; i < document.forms['orderform'].package.length; i++) {
		if (document.forms['orderform'].package[i].checked) {
			var package = parseInt(document.forms['orderform'].package[i].value);
		}
	}
	
	// get pages value
	var pages = parseInt(document.getElementById('pages-field').value);
	
	if ((pages <= 0) || (isNaN(pages))) {
		pages=0;
		document.getElementById('total-value').innerHTML = "$0";
		return;
	}

	var pages_package = 0;

	if (pages == 1) {
		pages_package = package;
	} else {
		pages_package = package;
		
		pages_package = pages_package + ( (pages - 1) * ((package * 75) / 100) );
	}

	// get CMS value
	for (var i=0; i < document.forms['orderform'].implementation.length; i++) {
		if (document.forms['orderform'].implementation[i].checked) {
			var cms = parseInt(document.forms['orderform'].implementation[i].value);
		}
	}
	
	// get Advanced Options
	var adv_options = 0;
	if (document.forms['orderform'].options_check_a.checked == true) { adv_options = adv_options + 10 ; }
	if (document.forms['orderform'].options_check_b.checked == true) { adv_options = adv_options + 5 ; }
	if (document.forms['orderform'].options_check_c.checked == true) { adv_options = adv_options + (19 * pages) ; }
	if (document.forms['orderform'].options_check_d.checked == true) { adv_options = adv_options + 30 ; }

	// CALCULATE TOTAL VALUE;
	totalvalue = pages_package + cms + adv_options;

	// get Express Delivery option
	var del_time = pages + 1;
	if (document.forms['orderform'].delivery_check.checked == true) {
		totalvalue = totalvalue + ((25 * totalvalue)/100);
		del_time = Math.round(pages / 2);
	}

	// get coupon discount
	var discount = parseInt(document.getElementById('discountvalue').value);
	if (discount > 0) {
		totalvalue = totalvalue - ((discount * totalvalue) / 100)
	}

	totalvalue = Math.round(totalvalue);

	// display Delivery Time
	document.getElementById('delivery_days').innerHTML = del_time + ' business days';

	document.getElementById('total-value').innerHTML = "$" + totalvalue;
}


function email_validate(email) {
   var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
   if(reg.test(email) == false) {
      return false;
   } else {
      return true;
   }
}

function validate_form() {
	if (email_validate(document.getElementById('email-field').value) == false) {
		alert("Please specify a valid email address");
		return false;
	}

	var pages_field=parseInt(document.getElementById('pages-field').value);
	if (isNaN(pages_field)) {
		pages_field=0;
	}

	if (pages_field <= 0) {
		alert("Please put the number of pages you want to order");
		return false;
	}
}