You can disable Ctrl + key combinations to protect your page. This will prevent user from copy and paste your web page.
<SCRIPT language=javascript type=text/javascript>
function disableCtrlKeyCombination(e)
{//list all CTRL + key combinations you want to disable
var forbiddenKeys = new Array(’a’, ‘n’, ‘c’, ‘x’, ‘v’, ‘j’);
var key;var isCtrl;
if(window.event)
{key = window.event.keyCode; //IE
if(window.event.ctrlKey)
isCtrl = true;
else
isCtrl = false;
}
else
{key = e.which; //firefox
if(e.ctrlKey)
isCtrl [...]

To start a new session you have to use the session_start() function.
session_start();
To check if a session variable exists:
if (!isset($_SESSION['variablename'])){
$_SESSION['variablename']=$valueofvariablename;  //session not set;
} else {
$valueofvariablename=$_SESSION['variablename']; //session already set;
}
If you want to end the session as a whole you can use the session_destroy() function.
session_destroy();
Well.. I think that’s enough!

Corner adorner in designing web has come to importance thing cause it will make your web looks better. For implementation of this, you can use rounded corner image as background or you can use javascript as I will explain below.