/*****************************************************************************
*
* Very Simple AJAX engine by U1I
* Version: 0.1
* copyright of this javascript code to U1I. Do not modify.
*
*****************************************************************************/

/*****************************************************************************
*
* HOWTO:
* 
* 1. Simple Document Request
*
*  loadXMLDoc(url, callback) 
*      In java script code space or event code space of any element,
*      call this function to request and receive a xml document.
*
*    url
*      The url of a xml document to download into current document.
*
*    callback
*      When the asyncronous response has arrived, this callback function is
*      called back with one argument arrived string data.
*
*  [EXAMPLE HTML CODE]
*   <script language="javascript" type="text/javascript">
*   function cb(responseText) {
*       document.getElementById("simpleReq").innerHTML = responseText;
*   }
*   </script>
*   <div id="simpleReq" onclick="loadXMLDoc('result.html?go=top', cb);">
*     Click Here
*   </div>
*
* 2. Document Request with Form data
*
*  submitFormToXMLDoc(form_id, callback)
*      In java script code space or event code space of any element,
*      call this function to request and receive a xml document.
*
*    form_id
*      The id of a form store form-elements containing data to use.
*
*    callback
*      When the asyncronous response has arrived, this callback function is
*      called back with one argument arrived string data.
*
*  [HTML CODE]
*   <script language="javascript" type="text/javascript">
*   function cbForm(responseText) {
*       document.getElementById("test").innerHTML = responseText;
*   }
*   </script>
*   <div id="test">posttest</div>
*   <form method="post" action="form.php" onsubmit="return submitFormToXMLDoc(this.id, cbForm);" id="frmPostTest">
*     <input type="text" name="option" value="value of the option element of form">
*     <input type="submit" value="post test">
*   </form>
*
*
*****************************************************************************/

var xmlHTTPReq = null;
var xmlHTTPReqCB = null;

/*
* some work to use XMLHTTPRequest Object
*/
function prepareXmlHTTPRequest()
{
	if(window.XMLHttpRequest) 
	{
		try 
		{
			xmlHTTPReq = new XMLHttpRequest();
		} 
		catch(e) 
		{
			xmlHTTPReq = false;
		}
	}
	else if(window.ActiveXObject) 
	{
		try 
		{
			xmlHTTPReq = new ActiveXObject("Msxml2.XMLHTTP");
		} 
		catch(e) 
		{
			try 
			{
				xmlHTTPReq = new ActiveXObject("Microsoft.XMLHTTP");
			} 
			catch(e) 
			{
				xmlHTTPReq = false;
			}
		}
	}
}

function processReqChange() 
{
	if (xmlHTTPReq.readyState == 4) 
	{ // Loaded
		if (xmlHTTPReq.status == 200) 
		{ // only if "OK"
			xmlHTTPReqCB(unescape(xmlHTTPReq.responseText));
		} 
		else 
		{
			alert("There was a problem retrieving the XML data:\n" + xmlHTTPReq.statusText);
		}
	}
}

/*
* Simple Call for requesting Document
*/
function loadXMLDoc(url, cb) 
{
	prepareXmlHTTPRequest();

	if (xmlHTTPReq) 
	{
		xmlHTTPReqCB = cb;
		xmlHTTPReq.onreadystatechange = processReqChange;

		try 
		{
			xmlHTTPReq.open("GET", url, true);
			xmlHTTPReq.send("");
		} 
		catch (e) 
		{
			alert("There may be one or more problem to execute XML request");
		}
	}

	delete xmlHTTPReq;
}

/*
* call of Form element for requesting Document
*/
function submitFormToXMLDoc(form_id, cb)
{
	var form;
	var method;
	var action;
	var postData = "";

	form = document.getElementById(form_id);

	if ( !form )
	{
		alert("check form id");
		return false;
	}

	method = form.method.toUpperCase();

	if ( !method ) 
	{
		alert("form must have an attribute 'method'");
		return false;
	}

	action = form.action;

	if ( !action ) 
	{
		alert("form must have an attribute 'action'");
		return false;
	}

	prepareXmlHTTPRequest();

	if (xmlHTTPReq) 
	{
		xmlHTTPReqCB = cb;
		xmlHTTPReq.onreadystatechange = processReqChange;
	}
	else 
	{
		return false;
	}

	if (method == "POST") 
	{
		xmlHTTPReq.open(method, action, true);

		if (xmlHTTPReq) 
		{
			for (i=0; i<form.elements.length; i++) 
			{
				if (form.elements[i].name) postData = postData + "&" + form.elements[i].name + "=" + escape(form.elements[i].value);
			}

			postData = postData.substr(1);
			xmlHTTPReq.setRequestHeader("Method", "POST " + action + " HTTP/1.1");
			xmlHTTPReq.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
			xmlHTTPReq.setRequestHeader("Content-Length", postData.length);
		}
	}
	else if (method == "GET") 
	{
		if (action.indexOf("?") == -1) action = action + "?";
		else action = action + "&";

		for (i=0; i<form.elements.length; i++) 
		{
			if (form.elements[i].name) 
			{
				action = action + "&" + form.elements[i].name + "=" + escape(form.elements[i].value);
			}
		}

		xmlHTTPReq.open(method, action, true);
		postData = null;
	}
	else 
	{
		alert("Unsupported Form Method: " + method);
		return false;
	}

	try 
	{
		xmlHTTPReq.send(postData);
	} 
	catch (e) 
	{
		alert("There may be one or more problem to execute XML request");
		delete xmlHTTPReq;
	}

	return false;
}