function validateString(input){
    if(input == ""){
        return false;
    }
    return true;
}

function validateEmail(input){
    var emailID = input;
    atpos = emailID.indexOf("@");
    dotpos = emailID.lastIndexOf(".");

    if (atpos < 1 || ( dotpos - atpos < 2 )) {
        return false;
    }
    return true;
}


function validateUser(){
    var name = document.forms["create_form"]["nombre"];
    var user = document.forms["create_form"]["usuario"];
    var password = document.forms["create_form"]["contraseña"];
    var email = document.forms["create_form"]["correo"];

    if(!validateString(name.value)){
        alert("Introduce el nombre");
        return false;
    }

    if(!validateString(user.value)){
        alert("Introduce el usuario");
        return false;
    }

    if(!validateString(password.value)){
        alert("Introduce la contraseña");
        return false;
    }

    if(!validateEmail(email.value)){
        alert("El correo proporcionado es incorrecto");
        return false;
    }
    
    return true;
}

function validateLogin(){
    var user = document.forms["login_form"]["usuario"];
    var password = document.forms["login_form"]["contraseña"];

    if(!validateString(user.value)){
        alert("Introduce el usuario");
        return false;
    }

    if(!validateString(password.value)){
        alert("Introduce la contraseña");
        return false;
    }
    return true;
}