function signUpClick(user, pass, pass2, mail) {
    window.alert(user + " " + pass + " " + mail);
    if (user == "" || pass == "" || pass2 == "" || mail == "") {
        window.alert("Check your information again.");
        return;
    }

    if (pass != pass2) {
        window.alert("Passwords do not match.");
        return;
    }
    var a = usersRef.orderByChild("username").equalTo(user).once('value').then(function (snapshot) {
        if (snapshot.val() !== null) {
            window.alert("user exists");
            return;
        } else {
            var re = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
            if (!re.test(String(mail).toLowerCase())) {
                window.alert("Double check your email.");
            } else {
                var b = usersRef.orderByChild("email").equalTo(mail).once('value').then(function (snapshot) {
                    if (snapshot.val() !== null) {
                        window.alert("email exists");

                        return;
                    } else {
                        newUser(user, pass, pass2, mail);
                    }
                });
            }
        }
    });

    var re = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    if (!re.test(String(mail).toLowerCase())) {
        window.alert("Double check your email.");
    } else {
        var b = usersRef.orderByChild("email").equalTo(mail).once('value').then(function (snapshot) {
            if (snapshot.val() !== null) {
                window.alert("email exists");

                return;
            } else {
                var a = usersRef.orderByChild("username").equalTo(user).once('value').then(function (snapshot) {
                    if (snapshot.val() !== null) {
                        window.alert("user exists");
                        return;

                    } else {
                        newUser(user, pass, pass2, mail);
                    }
                });
            }
        });
    }
    window.alert("End of signUpClick");
}