// @libname	ajaxlib.js



function createHttpRequest() {
	var http_request = null;
	if (window.XMLHttpRequest) { // for Gecko browser(firefox/opera/safari)
		http_request = new XMLHttpRequest();
	} else if (window.ActiveXObject) { // for IE 4.x, 5.x, 6.x
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
			//http_request = new XMLHttpRequest(); // for ie7?
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e2) {
				return null;
			}
		}
	} else {
		return null;
	}
	
	return http_request;
}

function chkAjaBrowser() {
	var a,ua = navigator.userAgent;
	this.bw= { 
	  safari    : ((a=ua.split('AppleWebKit/')[1])?a.split('(')[0].split('.')[0]:0)>=124 ,
	  konqueror : ((a=ua.split('Konqueror/')[1])?a.split(';')[0]:0)>=3.3 ,
	  mozes     : ((a=ua.split('Gecko/')[1])?a.split(' ')[0]:0) >= 20011128 ,
	  opera     : (!!window.opera) && ((typeof XMLHttpRequest)=='function') ,
	  msie      : (!!window.ActiveXObject)?(!!createHttpRequest()):false 
	}
	return (this.bw.safari||this.bw.konqueror||this.bw.mozes||this.bw.opera||this.bw.msie)
}

/**
 * callback		callback function or {onload: function, onbeforesetheader: func}
 * argus		
 * data			the data want to send. For example: &name1=value1&name2=value2&name3=value3.... 
 * method		'POST' or 'GET'
 * url			request url
 * async		true:async | false: sync
 * sload		true:forced load | false: defalut
 * user			username if needed
 * password		password if needed
 */
function sendRequest(callback,argus,data,method,url,async,sload,user,password) {
	var request = createHttpRequest();
	if( request == null )
		return null;
	
	var sload = (!!sendRequest.arguments[5])?sload:false;
	if(sload || method.toUpperCase() == 'GET')url += '?';
	if(sload)url=url+'t='+(new Date()).getTime();
		
	var bwoj = new chkAjaBrowser();
	var opera	  = bwoj.bw.opera;
	var safari	  = bwoj.bw.safari;
	var konqueror = bwoj.bw.konqueror;
	var mozes	  = bwoj.bw.mozes ;
	
	if(typeof callback == 'object') {
		var callback_onload = callback.onload;
		var callback_onbeforsetheader = callback.onbeforsetheader;
	} else {
		var callback_onload = callback;
		var callback_onbeforsetheader = null;
	}

	if(opera || safari || mozes) {
		request.onload = function () { 
			if (argus) {
				//if (request.overrideMimeType) // some Mozilla browser doesn't contain the header
				//	request.overrideMimeType('text/xml');
				callback_onload(request, argus);
			} else {
				//if (request.overrideMimeType)
				//	request.overrideMimeType('text/xml');
				callback_onload(request);
			}
		}
	} else {	
		request.onreadystatechange = function () {
			if ( request.readyState == 4 ){
				//alert(request.status+'--'+request.getAllResponseHeaders());
				if (argus) {
					//if (request.overrideMimeType)
					//	request.overrideMimeType('application/xml');
					callback_onload(request, argus);
				} else {
					//if (request.overrideMimeType)
					//	request.overrideMimeType('application/xml');
					callback_onload(request);
				}
			}
		}
	}

	data = uriEncode(data,url);
	if(method.toUpperCase() == 'GET') {
		url += data
	}

	request.open(method,url,async,user,password);

	if(!!callback_onbeforsetheader) {
		callback_onbeforsetheader(request);		
	}

	setEncHeader(request);
		
	request.send(data);

	function setEncHeader(request) {
		var contentTypeUrlenc = 'application/x-www-form-urlencoded; charset=UTF-8';
		if(!window.opera){
			request.setRequestHeader('Content-Type',contentTypeUrlenc);
		} else {
			if((typeof request.setRequestHeader) == 'function')
				request.setRequestHeader('Content-Type',contentTypeUrlenc);
		}	
		return request
	}

	function uriEncode(data,url) {
		var encdata =(url.indexOf('?')==-1)?'?dmy':'';
		if(typeof data=='object'){
			for(var i in data)
				encdata+='&'+encodeURIComponent(i)+'='+encodeURIComponent(data[i]);
		} else if(typeof data=='string'){
			if(data=='')return '';
	
			var encdata = '';
			var datas = data.split('&');
			for(var i=1;i<datas.length;i++) {
				var dataq = datas[i].split('=');
				encdata += '&'+encodeURIComponent(dataq[0])+'='+encodeURIComponent(dataq[1]);
			}
		} 
		return encdata;
	}

	return request;
}