async void OnLoginButtonClicked(object sender, EventArgs e)
{
var user = new User {
Email = emailEntry.Text,
Password = passwordEntry.Text
};
userDB = new UserDatabase();
if (userDB.AreCredentialsValid(user))
{
Navigation.InsertPageBefore(new HomePageCS(), this);
await Navigation.PopAsync();
}
else
{
messageLabel.Text = "Login failed";
passwordEntry.Text = string.Empty;
}
}