How to validate texbox using asp.net bootstrap error?

Question

Hi Team

 

I am having a form with textbox and dont know how to validate the textbox, the validation has to happens when user leaves the form with empty field inserted. Message " This field is required". Here is my logic but its not validating and need some help.

<div class="row">
                  <label for"Email">Email:</label>
                  <div class="input-group col-md-4 col-md-offset-2 col-sm-2 col-xs-2">
                      <div class="input-group pull-right">

                          @Html.TextBoxFor(m => m.Email, new { @class = "form-control", type = "text", id = "email", autofocus = "autofocus", placeholder = "[email protected]", required = "required" })

                          <div class="input-group-append">
                              <div class="input-group-text">

                              </div>
                          </div>
                      </div>
                  </div>
              </div>

div class="input-group mb-2">
                      <div class="input-group-append">

                      </div>
                      <div class="input-group col-md-4 col-md-offset-2 col-sm-2 col-xs-2">
                          <div class="input-group pull-right">

                              @Html.TextBoxFor(m => m.Code, new
                              {
                                  @class = "form-control",
                                  type = "text",
                             id = "postal code",
                                  autofocus = "autofocus",
                                  placeholder = "Postal / Zip Code",
                             required = "required",
                             pattern = @"[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$",
                            title = "This field is required"
                              })

                              <div class="input-group-append">
                                  <div class="input-group-text">

                                  </div>
                              </div>

                          </div>
                      </div>
                  </div>