Tiny AJAX lib

ajax.js

ajax = {
    getHTTPObject : function() {
		var http = false;
		//Use IE's ActiveX items to load the file.
		if(typeof ActiveXObject != 'undefined') {
			try {http = new ActiveXObject('Msxml2.XMLHTTP');}
			catch (e) {
				try {http = new ActiveXObject('Microsoft.XMLHTTP');}
				catch (E) {http = false;}
			}
		//If ActiveX is not available, use the XMLHttpRequest of Firefox/Mozilla etc. to load the document.
		} else if (window.XMLHttpRequest) {
			try {http = new XMLHttpRequest();}
			catch (e) {http = false;}
		}
		return http;
	},
	
	load : function (url, callback, format, method, data) {
		var httpObj = this.init();
		
		if (!method) method = 'GET';
		if (!format) format = 'text';
		
		if (!httpObj || !url) return;
		
		if (httpObj.overrideMimeType && format == 'json') {
		    httpObj.overrideMimeType('application/json');
		}
		
		var format = format.toLowerCase();
		var method = method.toUpperCase();
		
		//Kill the Cache problem in IE.
		var now = 'uid=' + new Date().getTime();
		url += (url.indexOf('?') + 1) ? '&' : '?';
		url += now;

		httpObj.open(method, url, true);

		httpObj.onreadystatechange = function () {
			if (httpObj.readyState == 4) {
			    var result = '';
				
				if(httpObj.responseText) {
				    result = httpObj.responseText;
			    }
				
				if(format == 'json' && result && JSON) {
					result = JSON.parse(result);
				}
				
				if(callback) {
				    callback(httpObj.status, result);
			    }
			}
		}
		
		httpObj.send(data);
	},
	init : function() { return this.getHTTPObject(); }
}