Javascript Loader (MAC)

Is there a way of getting javascript to load or reload on a mac?

At the moment I use this function Code:

function addScript(js) {
mybody=document.getElementsByTagName("body")[0];
newScript = document.createElement("SCRIPT");
mybody.appendChild(newScript);
newScript.setAttribute("type","text/javascript");
newScript.setAttribute("src",js);
}

but it doesn't seem to work on the mac.

I know I have the option of working with xml, but why would I want to create another output when my script already has a html output.

I use it like this (php)
Code:

$html="";
$html.="<h1>livescript</h1><p><a href=http://www.sitepoint.com title="sitepoint">Sitepoint</a>";

if($_GET["live"]=="on"){
header("ContentType: application/x-javascript");
echo "document.getElementsByTagName("body")[0].innerHTML="".preg_replace("/"/","'",$html).""";
} else echo $html;

works nicely, but not on a mac.