Poblema con funcion

[lokoguille2005]

Hola
Tengo poblema con una funcion php, en la cual no me dice donde esta el error ni nada, lo lei 20 veces y aun no lo encuentro. Se lo dejo a ver si ustedes se dan cuenta gracias

codigo
<?php
// constants to define the title of the alert and button text.
var ALERT_TITLE = "Oops!";
var ALERT_BUTTON_TEXT = "Ok";

// over-ride the alert method only if this a newer browser.
//Older browser will see standard alerts
if(document.getElementById) {
window.alert = function(txt) {
createCustomAlert(txt);
}
}

function createCustomAlert(txt) {
// shortcut reference to the document object
d = document;

// if the modalContainer object already exists in the DOM, bail out.
if(d.getElementById("modalContainer")) return;

// create the modalContainer div as a child of the BODY element
mObj = d.getElementsByTagName("body")[0].appendChild(d.createElement("div"));
mObj.id = "modalContainer";
// make sure its as tall as it needs to be to overlay all the content on the page
mObj.style.height = document.documentElement.scrollHeight + "px";

// create the DIV that will be the alert
alertObj = mObj.appendChild(d.createElement("div"));
alertObj.id = "alertBox";
// MSIE doesnt treat position:fixed correctly, so this compensates for positioning the alert
if(d.all && !window.opera) alertObj.style.top = document.documentElement.scrollTop + "px";
// center the alert box
alertObj.style.left = (d.documentElement.scrollWidth - alertObj.offsetWidth)/2 + "px";

// create an H1 element as the title bar
h1 = alertObj.appendChild(d.createElement("h1"));
h1.appendChild(d.createTextNode(ALERT_TITLE));

// create a paragraph element to contain the txt argument
msg = alertObj.appendChild(d.createElement("p"));
msg.innerHTML = txt;

// create an anchor element to use as the confirmation button.
btn = alertObj.appendChild(d.createElement("a"));
btn.id = "closeBtn";
btn.appendChild(d.createTextNode(ALERT_BUTTON_TEXT ));
btn.href = "#";
// set up the onclick event to remove the alert when the anchor is clicked
btn.onclick = function() { removeCustomAlert();return false; }


}

// removes the custom alert from the DOM
function removeCustomAlert() {
document.getElementsByTagName("body")[0].removeChild(document.getElementById("modalContain er"));
}
?>