var Ajax = XHR.extend({

	options: {
		data: null,
		update: null,
		onComplete: Class.empty,
		evalScripts: false,
		evalResponse: false
	},

	initialize: function(url, options){
		this.addEvent('onSuccess', this.onComplete);
		this.setOptions(options);
		/*compatibility*/
		this.options.data = this.options.data || this.options.postBody;
		/*end compatibility*/
		if (!['post', 'get'].contains(this.options.method)){
			this._method = '_method=' + this.options.method;
			this.options.method = 'post';
		}
		this.parent();
		this.setHeader('X-Requested-With', 'XMLHttpRequest');
		this.setHeader('Accept', 'text/javascript, text/html, application/xml, text/xml, */*');
		this.url = url;
	},

	onComplete: function(){
		if (this.options.update) $(this.options.update).empty().setHTML(this.response.text);
		if (this.options.evalScripts || this.options.evalResponse) this.evalScripts();
		this.fireEvent('onComplete', [this.response.text, this.response.xml], 20);
	},

	/*
	Property: request
		Executes the ajax request.

	Example:
		>var myAjax = new Ajax(url, {method: 'get'});
		>myAjax.request();

		OR

		>new Ajax(url, {method: 'get'}).request();
	*/

	request: function(data){
		data = data || this.options.data;
		switch($type(data)){
			case 'element': data = $(data).toQueryString(); break;
			case 'object': data = Object.toQueryString(data);
		}
		if (this._method) data = (data) ? [this._method, data].join('&') : this._method;
		return this.send(this.url, data);
	},

	/*
	Property: evalScripts
		Executes scripts in the response text
	*/

	evalScripts: function(){
		var script, scripts;
		if (this.options.evalResponse || (/(ecma|java)script/).test(this.getHeader('Content-type'))) scripts = this.response.text;
		else {
			scripts = [];
			var regexp = /<script[^>]*>([\s\S]*?)<\/script>/gi;
			while ((script = regexp.exec(this.response.text))) scripts.push(script[1]);
			scripts = scripts.join('\n');
		}
		if (scripts) (window.execScript) ? window.execScript(scripts) : window.setTimeout(scripts, 0);
	},

	/*
	Property: getHeader
		Returns the given response header or null
	*/

	getHeader: function(name){
		try {return this.transport.getResponseHeader(name);} catch(e){};
		return null;
	}

});