Prova con il codice che ti metto,dopo lo potrai sempre modificare come meglio vorrai.

Codice PHP:
<html>
    <head>
    <title>prova</title>
    <script type='text/javascript'>
        function cambiadiv(iddiv)
        {
            document.getElementById("principale").innerHTML=document.getElementById(iddiv).innerHTML;
        }
    </script>
    </head>
    <body>
        <div id="principale" style="padding:10px;width:200px;border:2px solid red">testo</div>        
        
        
        [url="#"]DIV 1[/url]
        [url="#"]DIV 2[/url]
        [url="#"]DIV 3[/url]        
        

        

        
        
        <div id="id1" style="margin-right:20px;float:left;padding:10px;width:200px;border:2px solid green">aaaaaaaaa</div>
        <div id="id2" style="margin-right:20px;float:left;padding:10px;width:200px;border:2px solid blue">bbbbbbb</div>
        <div id="id3" style="margin-right:20px;float:left;padding:10px;width:200px;border:2px solid black">ccccccc</div>        
    </body>
</html>