<script src="~/Scripts/jquery-2.1.1.min.js"></script>

    $(document).ready(function () {
    var Fname = $('#FirstName').attr("value");
    var Lname = $('#LastName').attr("value");
    var Email = $('#Email').attr("value");
    var Comment = $('#Comment').attr("value");
    $(".btn-primary").click(function () //This block should say, if all fields are not null changed the content of button to "Success!" and change the content of <h1> to "THANKS, I'VE GOT YOUR MESSAGE."
    {

        if (Fname != null && Lname != null && Email != null && Comment != null)
        {
            $("button").html("Success!");
            $("h1").html("THANKS, I'VE GOT YOUR MESSAGE");
        }

    })
});
</script>

<form class="form-horizontal" role="form" action="/Home/Contact" method="post">

                    <div class="form-group">

                        <div class="col-lg-10">

                            <input class="form-control" data-val="true" data-val-required="Please enter your first name" id="FirstName" type="text"  placeholder="First Name" name="FirstName"/>

                        </div>
                    </div>

                    <div class="form-group">
                        <div class="col-lg-10">
                            <input class="form-control" required data-val="true" data-val-required="Please enter your last name" id="LastName"  type="text" placeholder="Last Name" name="LastName"/>
                            <span class="field-validation-valid text-danger" data-valmsg-for="LastName" data-valmsg-replace="true" data-></span>
                        </div>
                    </div>

                    <div class="form-group">
                        <div class="col-md-10">

                            <input class="form-control" required data-val="true" data-val-required="Please enter your email" id="Email" name="Email" type="email" placeholder="Email@Address.com"/>
                            <span class="field-validation-valid text-danger" data-valmsg-for="Email" data-valmsg-replace="true"></span>
                        </div>
                    </div>

                    <div class="form-group">
                        <div class="col-lg-10">

                            <textarea class="form-control" required data-val="true" data-val-required="Please enter a brief detailed message" id="Comment" name="Comment" placeholder="A Short but detailed message"></textarea>
                            <span class="field-validation-valid text-danger" data-valmsg-for="Comment" data-valmsg-replace="true"></span>
                        </div>
                    </div>
                    <div class="form-group">
                        <div class="col-lg-10">
                            <button type="submit" class="btn btn-primary btn-sm active" value="submit">Submit</button>
                            <input type="reset" class="btn btn-default btn-sm active" value="reset">
                        </div>
                    </div>
                </form>