function hide_show(Id){
    var div = document.getElementById(Id);
    if (div.style.display == "none"){
        div.style.display = "block";
    }else{
        div.style.display = "none";
    }
}

function limitlength(obj, length){
    var maxlength=length
    if (obj.value.length>maxlength){
        obj.value=obj.value.substring(0, maxlength);
        alert('Has arribat màxim de caràcters.');
    }
}

function fons_menu(){
    alert("Funciona");
}