function makeRequest(url) {
		var http_request = false;
    var contenedor;
    contenedor = document.getElementById('content');
		
		var date = new Date();
		var timestamp = date.getTime();
	
        http_request = false;

        if (window.XMLHttpRequest) { // Mozilla, Safari,...
            http_request = new XMLHttpRequest();
            if (http_request.overrideMimeType) {
                http_request.overrideMimeType('text/xml');
                // Ver nota sobre esta linea al final
            }
        } else if (window.ActiveXObject) { // IE
            try {
                http_request = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
                try {
                    http_request = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) {}
            }
        }

        if (!http_request) {
            alert('Falla :( No es posible crear una instancia XMLHTTP');
            return false;
        }
        
        http_request.onreadystatechange = function(){ 

        if (http_request.readyState == 4) { 
            if (http_request.status == 200) { 
                urchinTracker("/"+url); 
                //alert("/"+url);
                contenedor.innerHTML = http_request.responseText
                
            } else { 
                contenedor.innerHTML = "Su navegador no soporta AJAX o se ha producido un error"
            }
        }
        };
        http_request.open('GET', url+"?time="+timestamp, true);
        http_request.send(null);

}

function cargar(url)
{
	pars = '';
	var myAjax = new Ajax.Request(
		url, 
		{ 
			method: 'get',
			parameters: pars,
			onComplete: mostrarTexto 
		}
	);
}

function mostrarTexto(originalRequest)
{
	$('content').innerHTML = originalRequest.responseText;
}

function validaFormulario(formulario) {

    //expresion regular para emails
    var email = /^(.+\@.+\..+)$/

		if(formulario.mensaje.value.length==0) { 
       alert('Rellena el mensaje.')
       return false
    }

    if(!email.test(formulario.email.value)) { 
       alert('E-MAIL no valido.')
       return false
    }

    return true
} 

function parametroGet( valor){
	var regexS = "[\\?&]"+valor+"=([^&#]*)";
	var regex = new RegExp ( regexS );
	var tmpURL = window.location.href;
	var results = regex.exec( tmpURL );
		
		if( results == null )
			return"";
		else
			return results[1];
}