Una posible solucion .
aun que na que ver con este foro ya que esta en Javascript, pero la gracia es que soluciones tu problema
Código PHP:
<html>
<head>
<title>Documento sin título</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css">
.dropcontent{
width: 300px;
height: 140px;
border: 1px solid black;
background-color: #FFECC6;
display:block;
}
</style>
<script type="text/javascript">
/*
Combo-Box Viewer script- Created by and ? Dynamicdrive.com
Visit [url]http://www.dynamicdrive.com/[/url] for this script and more
This notice MUST stay intact for legal use
*/
if (document.getElementById){
document.write('<style type="text/css">\n')
document.write('.dropcontent{display:none;}\n')
document.write('</style>\n')
}
function contractall(){
if (document.getElementById){
var inc=0
while (document.getElementById("dropmsg"+inc)){
document.getElementById("dropmsg"+inc).style.display="none"
inc++
}
}
}
function expandone(){
if (document.getElementById){
var selectedItem=document.dropmsgform.dropmsgoption.selectedIndex
contractall()
document.getElementById("dropmsg"+selectedItem).style.display="block"
}
}
if (window.addEventListener)
window.addEventListener("load", expandone, false)
else if (window.attachEvent)
window.attachEvent("onload", expandone)
</script>
</head>
<body>
<form name="dropmsgform">
<select name="dropmsgoption" size="1" style="width:300" onChange="expandone()">
<option selected>What is JavaScript?</option>
<option>Difference betwen Java and JavaScript</option>
<option>What is DHTML?</option>
</select>
<br>
<div id="dropmsg0" class="dropcontent">
JavaScript is a scripting language originally developed by Netscape to add interactivity and power to web documents. It is purely client side, and runs completely on the client's browser and computer.
</div>
<div id="dropmsg1" class="dropcontent">
Java is completely different from JavaScript- it's more powerful, more complex, and unfortunately, a lot harder to master. It belongs in the same league as C, C++, and other more complex languages. Java programs need to be compiled before they can run, while JavaScript do not.
</div>
<div id="dropmsg2" class="dropcontent">
DHTML is the embodiment of a combination of technologies- JavaScript, CSS, and HTML. Through them a new level of interactivity is possible for the end user experience.
</div>
</form>
</body>
</html>