$(document).ready(function () {
    $('#btnSignUp').click(function () {

        var email = ('#txtEmail').val();
        var username = ('#txtUsername').val()
        var password= ('#txtSifre').val();



        $.ajax({
            url: '/Uye/SignUp',
            data: { email: email, username: username, password: password},
            datatype: 'Json',
            type: 'Post'

        }).done(function () {
            $('#success').show(500);
        })

    })
})

public ActionResult SignUp(string email,string username,string password)
    {
        var data = db.Users.Where(x => x.Nick == username || x.Email==email).SingleOrDefault();
        Users user= new Users();
        if (data== null)
        {
            ModelState.AddModelError("", "Username is valid");
        }
        else
        {
            uye.Nick = username;
            uye.Email = email;
            uye.Password= password;

            db.Users.Add(user);
            db.SaveChanges();
        }

        return RedirectToAction("HomePage","Home");
    }