How to perform multiple field search in Entity Framework

This way

    protected void Button1_Click(object sender, EventArgs e)
    {
        ContactsDBEntities contactsDB = new ContactsDBEntities();
        var contacts = from Contact c in contactsDB.Contacts
                       where ((c.City == txtCity.Text || txtCity.Text == "") && (c.Country == txtCountry.Text || txtCountry.Text == ""))
                       select c;
    }