/*
url-loading object and a request queue built on top of it
*/

/* namespacing object */
var net=new Object();

net.READY_STATE_UNINITIALIZED=0;
net.READY_STATE_LOADING=1;
net.READY_STATE_LOADED=2;
net.READY_STATE_INTERACTIVE=3;
net.READY_STATE_COMPLETE=4;


/*--- content loader object for cross-browser requests ---*/
net.ContentLoader=function(url,onload,onerror,method,params,contentType){
	this.req=null;
	this.onload=onload;
	this.onerror=(onerror) ? onerror : this.defaultError;
	this.loadXMLDoc(url,method,params,contentType);
}

net.ContentLoader.prototype.loadXMLDoc=function(url,method,params,contentType){
	if (!method){
		method="GET";
	}
	if (!contentType && method=="POST"){
		contentType='application/x-www-form-urlencoded';
	}

	if (window.ActiveXObject){
		this.req=new ActiveXObject("Microsoft.XMLHTTP");
	}else if (window.XMLHttpRequest){
		this.req=new XMLHttpRequest();
	}

	if (this.req){
		try{
			var loader=this;
			this.req.onreadystatechange=function(){
				net.ContentLoader.onReadyState.call(loader);
			}
			this.req.open(method,url,true);
			if (contentType){
				this.req.setRequestHeader('Content-Type', contentType);
			}
			this.req.send(params);
		}catch (err){
			this.onerror.call(this);
		}
	}
}


net.ContentLoader.onReadyState=function(){
	var req=this.req;
	var ready=req.readyState;
	if (ready==net.READY_STATE_COMPLETE){
		var httpStatus=req.status;
		if(httpStatus==200 || httpStatus==0){
			this.onload.call(this);
		}else{
			this.onerror.call(this);
		}
	}
}

net.ContentLoader.prototype.defaultError=function(){
	alert("error fetching data!"
		+"\n\nreadyState:"+this.req.readyState
		+"\nstatus: "+this.req.status
		+"\nheaders: "+this.req.getAllResponseHeaders());
}



// FF ¶§¹®¿¡ Ãß°¡ÇÔ
//

// check for XPath implementation
if( document.implementation.hasFeature("XPath", "3.0") )
{
	// prototying the XMLDocument
	XMLDocument.prototype.selectNodes = function(cXPathString, xNode)
	{
		if( !xNode ) { xNode = this; }
		var oNSResolver = this.createNSResolver(this.documentElement)
		var aItems = this.evaluate(cXPathString, xNode, oNSResolver,XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null)
		var aResult = [];
		for( var i = 0; i < aItems.snapshotLength; i++)
		{
			aResult[i] =  aItems.snapshotItem(i);
		}
		return aResult;
	}

	// prototying the Element
	Element.prototype.selectNodes = function(cXPathString)
	{
		if(this.ownerDocument.selectNodes)
		{
			return this.ownerDocument.selectNodes(cXPathString, this);
		}
		else{throw "For XML Elements Only";}
	}
}


// check for XPath implementation
if( document.implementation.hasFeature("XPath", "3.0") )
{
	// prototying the XMLDocument
	XMLDocument.prototype.selectSingleNode = function(cXPathString, xNode)
	{
		if( !xNode ) { xNode = this; }
		var xItems = this.selectNodes(cXPathString, xNode);
		if( xItems.length > 0 )
		{
			return xItems[0];
		}
		else
		{
			return null;
		}
	}

	// prototying the Element
	Element.prototype.selectSingleNode = function(cXPathString)
	{
		if(this.ownerDocument.selectSingleNode)
		{
			return this.ownerDocument.selectSingleNode(cXPathString, this);
		}
		else{throw "For XML Elements Only";}
	}
}