how to use more than 1 plugins for same page or site

how to use more than 1 plugins for same page or site

I am using 2 plugins for same page that is cycle plugin and rounded corner pluging.
but when I adds up lightbox into the same page nothing is working.
I am using this coding 
please help me

<link rel="stylesheet" href="css/lightbox.css" type="text/css" media="screen" />  
<link rel="stylesheet" href="css/style.css" rel="stylesheet" type="text/css" />
<script type="text/javascript" src="js/prototype.js"></script>
<script type="text/javascript" src="js/scriptaculous.js?load=effects,builder"></script>
<script type="text/javascript" src="js/lightbox.js"></script>
<script type="text/javascript" src="scripts/jquery-1.4.2.js"></script>
<SCRIPT type="text/javascript" src="scripts/jquery.corner.js"></SCRIPT>
<SCRIPT language="JavaScript" SRC="scripts/script.js"></SCRIPT>