function createXmlHttpRequestObject() {
	var xmlHttp;
	try {
		xmlHttp = new XMLHttpRequest();
	} catch(e) {
		var XmlHttpVersions = new Array(	'MSXML2.XMLHTTP.6.0',
											'MSXML2.XMLHTTP.5.0',
											'MSXML2.XMLHTTP.4.0',
											'MSXML2.XMLHTTP.3.0',
											'MSXML2.XMLHTTP',
											'Microsoft.XMLHTTP');
		for (var i=0; i<XmlHttpVersions.length && !xmlHttp; i++) {
			try {
				xmlHttp = new ActiveXObject(XmlHttpVersions[i]);
			} catch(e) {}
		}
	}
	if (!xmlHttp) {
		alert("Error en crear l'objecte XMLHttpRequest.");
	} else {
		return xmlHttp;		
	}
}

function displayLoading(element) {
	while(element.hasChildNodes()) {
		element.removeChild(element.lastChild);
	}
	var image = document.createElement('img');
	image.setAttribute('src', '../imatges/lightbox/loading.gif');
	image.setAttribute('alt', 'Carregant');
	image.setAttribute('id', 'img_loading');
	element.appendChild(image);
}