title: MVC Validation attributes are not working
body: <p>MVC Validation attributes are not working. When i hit the Submit button without entering any data in add view,it supposed to throw an Validation error but it's not throwing validation error. 
  I have added validation attributes to the model and also check ModelState property, but still it's not working</p>
  
  <p>In my config file,have the below settings</p>
  
  <pre><code>&lt;add key="ClientValidationEnabled" value="true" /&gt;
  &lt;add key="UnobtrusiveJavaScriptEnabled" value="true" /&gt;
  </code></pre>
  
  <p>Below is the model I'm refering to the view.</p>
  
  <pre><code>public class Student
  {
      public int StuID { get; set; }
  
      [DisplayName("Student Name")]
      [Required(ErrorMessage = "Name Required!")]
      public string StuName  { get; set; }
  
      [Required(ErrorMessage = "Please Mention Education!")]
      public string Education { get; set; }
  
      [DisplayName("Birth Date")]
      public DateTime? BirthDate { get; set; }
  
      [DisplayName("Gender")]
      public string Sex { get; set; }
  
      [Required(ErrorMessage = "Please Enter Course Name!")]
      public string Course { get; set; }
      //public string Location { get; set; }
  
      [DisplayName("Location")]
      public int LocID { get; set; }
  
      [RegularExpression(@"^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$", ErrorMessage = "Invalid Phone number")]
      [Required(ErrorMessage = "Phone Number Required!")]
      public String Contact { get; set; }
  }
  </code></pre>
  
  <p>Controller :</p>
  
  <pre><code>    public ActionResult Add(Student student)
      {
          if (ModelState.IsValid)
          {
              using (SqlConnection SqlCon = new SqlConnection(conn))
              {
                  SqlCon.Open();
                  SqlCommand cmd = new SqlCommand("INSERT INTO Student(StuName,Education,Sex,Course,BirthDate,LocID,Contact) Values(@StuName,@Education,@Sex,@Course,@BirthDate,@LocID,@Contact) ", SqlCon);
                  cmd.Parameters.AddWithValue("@StuName", student.StuName);
                  cmd.Parameters.AddWithValue("@Education", student.Education);
                  cmd.Parameters.AddWithValue("@Sex", student.Sex);
                  cmd.Parameters.AddWithValue("@Course", student.Course);
                  cmd.Parameters.AddWithValue("@BirthDate", student.BirthDate.HasValue ? (object)student.BirthDate : DBNull.Value);
                  cmd.Parameters.AddWithValue("@LocID", student.LocID);
                  cmd.Parameters.AddWithValue("@Contact", string.IsNullOrEmpty(student.Contact) ? DBNull.Value : (object)student.Contact);
                  cmd.ExecuteNonQuery();
              }
          }
          return View();
      }
  </code></pre>
  
  <p>I have checked the <strong>ModelState</strong> property also in controller but still it is not working. Am i missing something here? </p>