hmm how will i start..
in my main page we can find the login form... that login form is made up of div... after i successfully logged in that login form div will become hidden then my other hidden div which is the control panel will appear.. that control panel will include the account details of the one who logged in..

$(document).ready(function() {
         $("#login_form").submit(function() {
            var unameval = $("#username").val();
            var pwordval = $("#password").val();
            $.cookie('username', username, { expires: 14 });
            $.post("backend.php", { username: unameval,
            password: pwordval }, function(data) {
               $("#status p").html(data);
            });
            return false;
         });
      });

function ShowLoginBox(){
            userName = $.cookie('username');
            if (userName != null && userName.length > 0) {
                $("#headerlogin").show();
                $("#headerlogin2").hide();
            }
            else
            {
                $("#headerlogin).hide();
                $("#headerlogin2").show();
            }
        }
       
        ShowLoginBox();

the above code is for hiding and showing the div.. the problem is how will i make it show after logging in.. after i logged in it will only print logged in successfully ..do i need to make cookies? thanks in advance

Yes please, make those cookies and set those sessions :)