Edit URL doesnt contain Id

I am learning MVC from

https://www.youtube.com/watch?v=ItSA19x4RU0&list=PL6n9fhu94yhVm6S8I2xd6nYz2ZORd7X2v

I am doing Basic Edit operation..Index Page shows following Data ..

Emp_id   Emp_name    Emp_Sal    
1         name1       sal1    Edit | Details | Delete

...When i click on Edit ..URL Display Like

"http://localhost/MvcApplication1/Employee/Edit"`

...But Accordng to Tutorial it should be like

http://localhost/MvcApplication1/Employee/Edit/01

the map Route is

  routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );

I have not create Edit ActionMethod till now .

Index View Code is :

@model IEnumerable<BusinessLayer.Employee>
@{
    ViewBag.Title = "Index";
}
<h2>
    Index</h2>
<p>
    @Html.ActionLink("Create New", "Create")
</p>
<table>
    <tr>

        <th>
            @Html.DisplayNameFor(model => model.Emp_id)
        </th>

        <th>
            @Html.DisplayNameFor(model => model.Emp_name)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.Emp_Sal)
        </th>
        <th>
        </th>
    </tr>
    @foreach (var item in Model)
    {
        <tr>
        <td>
                @Html.DisplayFor(modelItem => item.Emp_id)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Emp_name)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Emp_Sal)
            </td>
            <td>
                @Html.ActionLink("Edit", "Edit", new { /* id=item.PrimaryKey */ }) |
                @Html.ActionLink("Details", "Details", new { /* id=item.PrimaryKey */ }) |
                @Html.ActionLink("Delete", "Delete", new { /* id=item.PrimaryKey */ })
            </td>
        </tr>
    }
</table>

Please Suggest if I am missing something

Your ActionLink calls don't pass the correct route values. The Edit, Details and Delete actions expect an id parameter to be passed as a route value. You can do this as follows, assuming the Emp_id is the id value you want to use:

@Html.ActionLink("Edit", "Edit", new { id=item.Emp_id }) |
@Html.ActionLink("Details", "Details", new { id=item.Emp_id }) |
@Html.ActionLink("Delete", "Delete", new { id=item.Emp_id })

In your example, you have these values commented so they won't be passed as route values and thus no correct route will be generated.