How to Enable Client Cookies in below Tab Selected Option.

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
    <script type="text/javascript" src="Scripts/domtab.js"></script>
    <script type="text/javascript">
        document.write('<style type="text/css">');
        document.write('div.domtab div{display:none;}<');
        document.write('/s' + 'tyle>');
    </script>
    <p id="domtabprintview">
    </p>
    <div class="domtab">
        <ul class="domtabs">
            <li><a href="#what">Knowlege Sharing Center</a></li>
            <li><a href="#how">Knowledge</a></li>
            <li><a href="#pr">Category</a></li>
            <li><a href="#style">Sub Category</a></li>
        </ul>
        <div>
            <a name="what" id="what">What is Dom Tab</a> What
            <asp:GridView ID="GridView1" runat="server">
            </asp:GridView>
        </div>
        <div>
            <a name="how" id="how">How to use DOMtab</a> DOMtab
        </div>
        <div>
            <a name="pr" id="pr">Previous and next links</a>Previous
        </div>
        <div>
            <a name="style" id="style">How to style DOMtab</a>How
        </div>
</asp:Content>

*{
  margin:0;
  padding:0;
  list-style:none;
  border:none;
  }
  ul.domtabs li{
  float:left;
  padding:0 .5em 0 0;
  }
  ul.domtabs a:link,
  ul.domtabs a:visited,
  ul.domtabs a:active,
  ul.domtabs a:hover{
  width:8em;
  padding:.2em 1em;
  display:block;
  background:#3a4f63;
  color:#fff;
  height:3em;
  text-decoration:none;
  }
  div.domtab div{
  clear:both;
  width:35.5em;
  background:#000033;
  color:#fff;
  padding:1em 3em;
  }
  h1{
  padding:1em 2;
  background:#fff;
  }

domtab = {
    tabClass: 'domtab',
    listClass: 'domtabs',
    contentElements: 'div',
    init: function () {

        var temp;
        if (!document.getElementById || !document.createTextNode) { return; }
        var tempelm = document.getElementsByTagName('div');
        for (var i = 0; i < tempelm.length; i++) {
            if (!domtab.cssjs('check', tempelm[i], domtab.tabClass)) { continue; }
            domtab.initTabMenu(tempelm[i]);
          //  domtab.removeBackLinks(tempelm[i]);
            if (domtab.cssjs('check', tempelm[i], domtab.prevNextIndicator)) {
              //  domtab.addPrevNext(tempelm[i]);
            }
           // domtab.checkURL();
        }
        if (document.getElementById(domtab.printID)
 && !document.getElementById(domtab.printID).
  getElementsByTagName('a')[0]) {
            var newlink = document.createElement('a');
            newlink.setAttribute('href', '#');
            domtab.addEvent(newlink, 'click', domtab.showAll, false);
            newlink.onclick = function () { return false; }
            newlink.appendChild(document.createTextNode(domtab.
  showAllLinkText));
            document.getElementById(domtab.printID).appendChild(newlink);
        }
    },

    initTabMenu: function (menu) {
        var id;
        var lists = menu.getElementsByTagName('ul');
        for (var i = 0; i < lists.length; i++) {
            if (domtab.cssjs('check', lists[i], domtab.listClass)) {
                var thismenu = lists[i];
                break;
            }
        }
        if (!thismenu) { return; }
        thismenu.currentSection = '';
        thismenu.currentLink = '';
        var links = thismenu.getElementsByTagName('a');
        for (i = 0; i < links.length; i++) {
            if (!/#/.test(links[i].getAttribute('href').toString()))
            { continue; }
            id = links[i].href.match(/#(\w.+)/)[1];
            if (document.getElementById(id)) {
                domtab.addEvent(links[i], 'click', domtab.showTab, false);
                links[i].onclick = function () { return false; }
                domtab.changeTab(document.getElementById(id), 0);
            }
        }
        id = links[0].href.match(/#(\w.+)/)[1];
        if (document.getElementById(id)) {
            domtab.changeTab(document.getElementById(id), 1);
            thismenu.currentSection = id;
            thismenu.currentLink = links[0];
            domtab.cssjs('add', links[0].parentNode, domtab.activeClass);
        }
    },


    changeTab: function (elm, state) {
        do {
            elm = elm.parentNode;
        } while (elm.nodeName.toLowerCase() != domtab.contentElements)
        elm.style.display = state == 0 ? 'none' : 'block';
    },
    showTab: function (e) {
        var o = domtab.getTarget(e);
        if (o.parentNode.parentNode.currentSection != '') {
            domtab.changeTab
  (document.getElementById(o.parentNode.parentNode.
  currentSection), 0);
            domtab.cssjs
  ('remove', o.parentNode.parentNode.currentLink.parentNode,
  domtab.activeClass);
        }
        var id = o.href.match(/#(\w.+)/)[1];
        o.parentNode.parentNode.currentSection = id;
        o.parentNode.parentNode.currentLink = o;
        domtab.cssjs('add', o.parentNode, domtab.activeClass);
        domtab.changeTab(document.getElementById(id), 1);
        document.getElementById(id).focus();
        //domtab.cancelClick(e);
    },

    getTarget: function (e) {
        var target = window.event ? window.event.srcElement :
   e ? e.target : null;
        if (!target) { return false; }
        if (target.nodeName.toLowerCase() != 'a') { target = target.parentNode; }
        return target;
    },

    addEvent: function (elm, evType, fn, useCapture) {
        if (elm.addEventListener) {
            elm.addEventListener(evType, fn, useCapture);
            return true;
        } else if (elm.attachEvent) {
            var r = elm.attachEvent('on' + evType, fn);
            return r;
        } else {
            elm['on' + evType] = fn;
        }
    },
    cssjs: function (a, o, c1, c2) {
        switch (a) {
            case 'swap': o.className = !domtab.cssjs
  ('check', o, c1) ? o.className.replace(c2, c1) : o.className.replace(c1, c2);
                break;
            case 'add':
                if (!domtab.cssjs('check', o, c1)) {
                    o.className +=
   o.className ? ' ' + c1 : c1;
                }
                break;
            case 'remove':
                var rep = o.className.match(' ' + c1) ? ' ' + c1 : c1;
                o.className = o.className.replace(rep, '');
                break;
            case 'check':
                var found = false;
                var temparray = o.className.split(' ');
                for (var i = 0; i < temparray.length; i++) {
                    if (temparray[i] == c1) { found = true; }
                }
                return found;
                break;
        }
    }
}
domtab.addEvent(window, 'load', domtab.init, false);