var http_request_page = false;

   function makePOSTRequest_page(url, parameters) {

      http_request_page = false;

      if (window.XMLHttpRequest) { // Mozilla, Safari,...

         http_request_page = new XMLHttpRequest();

         if (http_request_page.overrideMimeType) {

         	// set type accordingly to anticipated content type

            //http_request.overrideMimeType('text/xml');

            http_request_page.overrideMimeType('text/html');

         }

      } else if (window.ActiveXObject) { // IE

         try {

            http_request_page = new ActiveXObject("Msxml2.XMLHTTP");

         } catch (e) {

            try {

               http_request_page = new ActiveXObject("Microsoft.XMLHTTP");

            } catch (e) {}

         }

      }

      if (!http_request_page) {

         alert('Cannot create XMLHTTP instance');

         return false;

      }

      

      http_request_page.onreadystatechange = alertContents_page;

      http_request_page.open('POST', url, true);

      http_request_page.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

      http_request_page.setRequestHeader("Content-length", parameters.length);

      http_request_page.setRequestHeader("Connection", "close");

      http_request_page.send(parameters);

   }



   function alertContents_page() {

   	document.getElementById('formAddPageSpan').innerHTML = '<div class="loader" align="center"><p><img src="/gfx/loading.gif"></p><p>Calculating ...</p><p>Please hold</p></div>';

      if (http_request_page.readyState == 4) {

         if (http_request_page.status == 200) {

            //alert(http_request.responseText);

            result = http_request_page.responseText;

            document.getElementById('formAddPageSpan').innerHTML = result;  

         } else {

            alert('There was a problem with the request.');

         }

      }

   }

   

   

   function get_page(obj) {

      var e_typeSelection = document.getElementById("e_type");
	  

      var poststr = "a=" + encodeURI( document.getElementById("a").value ) +

	  "&b=" + encodeURI( document.getElementById("b").value ) +
	  
	  "&c=" + encodeURI( document.getElementById("c").value ) +
	  
	  "&d=" + encodeURI( document.getElementById("d").value ) +
	  
	  "&e=" + encodeURI( document.getElementById("e").value ) +
	  
	  "&e_type=" + encodeURI( e_typeSelection.options[e_typeSelection.selectedIndex].value );



	  

      makePOSTRequest_page('/calculate.php', poststr);

	  document.getElementById('showPageAddForm').style.display = 'none';

   }