While writing codes in MVC there is need for using javascript in the code.
 

So for doing that we need to put the library for it and adding the library bundle into the code.

 $(document).ready(function () {
        $(".editLink").click(function (e) {
            var a = $(this).attr('name');
            $("#lblEmpId" + a).hide();
            $("#txtEmpId" + a).show();
            $("#lblFirstName" + a).hide();
            $("#txtFirstName" + a).show();
            $("#lblMiddleName" + a).hide();
            $("#txtMiddleName" + a).show();
            $("#lblLastName" + a).hide();
            $("#txtLastName" + a).show();
            $("#lblAddress" + a).hide();
            $("#txtAddress" + a).show();
            $("#lblPhoneNo" + a).hide();
            $("#txtPhoneNo" + a).show();
            e.preventDefault();
            $("#editlnk" + a).hide();
            $("#updlnk" + a).show();
            $("#cancellnk" + a).show();
        });



        $(".updateLink").click(function (e) {
            var a = $(this).attr('name');
            alert(a);
            var EmployeeModel = {};
            EmployeeModel.EmpId = $("#txtEmpId" + a).val();
            EmployeeModel.FirstName = $("#txtFirstName" + a).val();
            EmployeeModel.MiddleName = $("#txtMiddleName" + a).val();
            EmployeeModel.LastName = $("#txtLastName" + a).val();
            EmployeeModel.Address = $("#txtAddress" + a).val();
            EmployeeModel.PhoneNo = $("#txtPhoneNo" + a).val();          

            $.ajax({
                type: "POST",
                url: "/RegisterGrid/UpdateUser",
                data: '{EmployeeDetails: ' + JSON.stringify(EmployeeModel) + '}',
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (response) {
                    alert(response.d);
                    window.location.reload();
                },
                error: function (response) {
                    alert("Some error occurred", "Error Description" + response.d);
                    window.location.reload();
                }
            });



            $("#lblEmpId" + a).show();
            $("#txtEmpId" + a).hide();
            $("#lblFirstName" + a).show();
            $("#txtFirstName" + a).hide();
            $("#lblMiddleName" + a).show();
            $("#txtMiddleName" + a).hide();
            $("#lblLastName" + a).show();
            $("#txtLastName" + a).hide();
            $("#lblAddress" + a).show();
            $("#txtAddress" + a).hide();
            $("#lblPhoneNo" + a).show();
            $("#txtPhoneNo" + a).hide();
            $("#editlnk" + a).show();
            $("#updlnk" + a).hide();
            $("#cancellnk" + a).hide();
            e.preventDefault();
        });


        $(".cancelLink").click(function (e) {
            var a = $(this).attr('name');
            $("#lblEmpId" + a).show();
            $("#txtEmpId" + a).hide();
            $("#lblFirstName" + a).show();
            $("#txtFirstName" + a).hide();
            $("#lblMiddleName" + a).show();
            $("#txtMiddleName" + a).hide();
            $("#lblLastName" + a).show();
            $("#txtLastName" + a).hide();
            $("#lblAddress" + a).show();
            $("#txtAddress" + a).hide();
            $("#lblPhoneNo" + a).show();
            $("#txtPhoneNo" + a).hide();
            $("#editlnk" + a).show();
            $("#updlnk" + a).hide();
            $("#cancellnk" + a).hide();
            e.preventDefault();
        });






    });

So for this we use the javascript for the enabling and disabling the elements and adding the bundle for the javascript .

@model MVC_Demo.Models.EmployeeModel

@{
    ViewBag.Title = "RegisterEmployee";
}
<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script> 




<h2>RegisterEmployee</h2>

@using (Html.BeginForm("RegisterEmployeeDetails", "Register", new { ReturnUrl = ViewBag.ReturnUrl }, FormMethod.Post, new { @class = "form-horizontal", role = "form" })) 
{
    @Html.AntiForgeryToken()
    
    <div class="form-horizontal">
        <h4>EmployeeModel</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div class="form-group">
            @Html.LabelFor(model => Model.FirstName, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => Model.FirstName, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => Model.FirstName, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => Model.MiddleName, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => Model.MiddleName, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => Model.MiddleName, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => Model.LastName, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => Model.LastName, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => Model.LastName, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => Model.PhoneNo, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => Model.PhoneNo, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => Model.PhoneNo, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => Model.Address, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => Model.Address, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => Model.Address, "", new { @class = "text-danger" })
            </div>
        </div>

  

        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
}

<div>
    @Html.ActionLink("Back to List", "Index")
</div>




@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}