function crear_elemento(nombre,atributos)
    {
        if ((document.all && navigator.appName.indexOf("Microsoft") >= 0) || nombre=="object") {
            var str = " ";
            if(atributos!=""){
                var arr = atributos.split(";");
                for(var i=0;i < arr.length;i++){
                    if((pos = arr[i].indexOf('='))>=0){
                        var arr2 = arr[i].split("=");
                        if(arr2.length==2) str += arr2[0]+"="+"'"+arr2[1]+"' ";
                        else str += arr2[0]+"="+"'"+arr[i].substring(pos+1,arr[i].length)+"' ";
                    }//if
                }//for
            }//if
            var elemento = document.createElement("<"+nombre+str+">");
        } else {
            var elemento = document.createElement(nombre);
            if(atributos!=""){
                var arr = atributos.split(";");
                for(var i=0;i < arr.length;i++){
                    if((pos = arr[i].indexOf('='))>=0){
                        var arr2 = arr[i].split("=");
                        if(arr2.length==2) elemento.setAttribute(arr2[0],arr2[1]);
                        else elemento.setAttribute(arr2[0],arr[i].substring(pos+1,arr[i].length));
                    }
                }//for
            }//if
        }//else
        return elemento;
    }//crear_elemento
    
    
    function enviar_amigo(idr)
    {
        var tr = document.getElementById("enviar_amigo");
        var padre = null;
        if (tr != null && (padre = tr.parentNode) != null) {
            var form = null;
            if ((form = document.getElementById("form_enviar_amigo")) == null) {
                form = crear_elemento("form","action=enviar_amigo.php;id=form_enviar_amigo");
                if(form != null){
                    var tr = crear_elemento("tr","id=tr_enviar_amigo_1");
                    var td = crear_elemento("td","colspan=3");
                    var input = crear_elemento("input","type=text;name=email;maxlength=70;size=50;id=email");
                    var submit = crear_elemento("input","type=button;name=enviar_amigo_bt;value=enviar;onclick=validar_ajax()");
                    var hidden = crear_elemento("input","type=hidden;name=idr;id=idr;value="+idr);
                    td.appendChild(document.createTextNode('Email: '));
                    td.appendChild(form);
                    form.appendChild(input);
                    form.appendChild(submit);
                    form.appendChild(hidden);
                    tr.appendChild(td);
                    padre.appendChild(tr);
                    document.getElementById("email").focus();
                }
            } else {
                if (document.getElementById("tr_enviar_amigo_1")) padre.removeChild(document.getElementById("tr_enviar_amigo_1"));
            }//else
        }//if
    }//ver_fecha
    
    function validar(form)
    {
        var men = "";
        var regexp = new RegExp("^[^@]+@[^@]+\.[^@]+$","gi");
    
        if (form.email.value == "" || !regexp.test(form.email.value)) {
            men = "Ha de especificar un email válido!!\n";
        }
        
        return men;
    }//validar
    
    
    function validar_ajax()
    {
        var form = document.getElementById("form_enviar_amigo");
        var req = null;
        var men = "";
        if ((men = validar(form)) == "") {

            if(window.XMLHttpRequest){
                req = new XMLHttpRequest();
                if(req.overrideMimeType){
                    req.overrideMimeType('text/xml');
                }
            } else if(window.ActiveXObject){
                try {
                    req = new ActiveXObject("Msxml2.XMLHTTP");
                } catch(e){
                    try {
                        req = new ActiveXObject("Microsoft.XMLHTTP");
                    } catch(e) {}
                }
            }//if

            if(!req){
                form.submit();
                return false;
            }

            req.onreadystatechange = function(){
                recoger_ok(req);
            };
            req.open('POST',form.action,true);
            req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
            var param = "idr="+form.idr.value+"&email="+form.email.value;
            req.send(param);

        } else alert(men);

    }//validar_ajax

    function recoger_ok(req)
    {
        var form = document.getElementById("form_enviar_amigo");
        var men = "";
        if (req.readyState == 4) {
            if (req.status == 200) {
                switch (req.responseText) {
                    case "<p>codigo=1</p>":
                        men = "Recurso enviado a " + form.email.value;
                    break;
                    case "<p>codigo=2</p>":
                        men = "No se pudo enviar el recurso a " + form.email.value;
                    break;
                    case "<p>codigo=3</p>":
                        men = "No existe la página del recurso.";
                    break;
                    case "<p>codigo=4</p>":
                        men = "No existe el recurso en la bbdd.";
                    break;
                    case "<p>codigo=5</p>":
                        men = "Los parámetros no son correctos.";
                    break;
                    default:
                        men = "Tu correo no se ha podido enviar. Disculpa las molestias.";
                }
                alert(men);
            } else {
                alert("Tu correo no se ha podido enviar. Disculpa las molestias.");
            }
        }
    }//recoger_ok