I think this is what you looking for
code:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Untitled Document</title>
</head>
<body>
<div id="poop">hello Wednesday</div>
<script language="javascript">
var element = document.getElementById("poop");
element.innerHTML = element.innerHTML.replace(/Wednesday/g, "Ooompa Loompa");
</script>
</body>
</html>
This code will replace all instances of Wednesday with Ooompa Loompa
/ 
