What is the difference between Abstraction and Encapsulation, better real time example.

how to get nth highest and lowest salary in sql server

Ex Code: Lowest case :

select top 1 column as 'salary' from (select distinct top 4 column from  Table order by ID asc) a order by ID desc

Highest Case:

select top 1 column as 'salary' from (select distinct top 4 column from  Table order by ID desc) a order by ID asc

linq get second highest number or salary

Use this query:

var employees = Employees
    .GroupBy(e => e.Salary)
    .OrderByDescending(f => f.Key)
    .Skip(1).Take(1)
    .First();

how to count number of online users in asp.net

Simple two steps:

1.Add this code in Global.asax

void Application_Start(Object Sender, EventArgs E)

        {

            Application["CurrentUsers"] = 0;

        }

        void Session_OnStart(object Sender, EventArgs E)

        {

            Application.Lock();

            Application["CurrentUsers"] = System.Convert.ToInt32(Application["CurrentUsers"]) + 1;

            Application.UnLock();

        }

        void Session_OnEnd(object Sender, EventArgs E)

        {

            Application.Lock();

            Application["CurrentUsers"] = System.Convert.ToInt32(Application["CurrentUsers"]) - 1;

            Application.UnLock();

        }

2.In Aspx Page

<%=Application["CurrentUsers"].ToString()%>

In web.config timeout will be make 10, by default 20

hex code for checkbox and apply to css

HEX Code for check box is :
                         Checked :2610,
                    Un Checked :2611.

In Css
.checked:before
{
    content:"\2611";
    }

in Aspx page or html page or View

<a href="#" class="checked"></a>

dynamic menu li selected item highlighted using jquery or javascript

Use the following steps for archiving li selected item highlited.

Loop Code :1

@foreach (class obj in list)
        {
            <ul>
                <li  class="@obj.strName" style="font-weight:bold;" ><a href="#"  style="text-decoration:none;" >
 </a></li>
            </ul>
        }

Css: 2
.li
    {      
        background-color:#bb0d2d !important;
        color: white !important;      
    }

JQuery: 3
$('li').click(function () {
        $(this).addClass('li');
    });

default button in html using jquery

use this steps:
Html or aspx or View
create textbox and button in the page and assign id,

Then,

JQUERY

$("#textboxID").keyup(function (event) {
        if (event.keyCode == 13) {
            $("#buttonID").click();
        }
    });