var bIsNC4 = (navigator.appName == "Netscape") && (parseInt(navigator.appVersion) >= 4);
	var bIsIE4 = (navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion) >= 4 );
	var bIsSupportOK = bIsNC4 || bIsIE4;
	
	var nMaxItem = 4;
	var NameIndex = 0;
	var DefaultState = 1;
	var MouseOverState = 2;
	var MouseDownState = 3;
	
	var imgCounter = 0;
	var ImageList = new Array();
	
	function AddImageToImageList(name, Default, MouseOver, MouseDown)
	{
		ImageList[imgCounter] = new Array(nMaxItem);
		ImageList[imgCounter][NameIndex] = name;
		ImageList[imgCounter][DefaultState] = new Image();
		ImageList[imgCounter][DefaultState].src = Default;
		if (MouseOver != "") {
			ImageList[imgCounter][MouseOverState] = new Image();
			ImageList[imgCounter][MouseOverState].src = MouseOver;
		}
		if (MouseDown != "") {
			ImageList[imgCounter][MouseDownState] = new Image();
			ImageList[imgCounter][MouseDownState].src = MouseDown;
		}
	
		imgCounter++;
	}
	
	function ReplaceImage(name, state)
	{
		if (bIsSupportOK) {
			for (i = 0; i < imgCounter; i++) {
				if (document.images[ImageList[i][NameIndex]] != null) {
					if ((name == ImageList[i][NameIndex]) && (ImageList[i][state] != null))
						document.images[name].src = ImageList[i][state].src;
				}
			}
		}
	}
	AddImageToImageList("rollover1", "images/header_7_normal.jpg", "images/header_7_over.jpg", "");
	AddImageToImageList("rollover2", "images/header_9_normal.jpg", "images/header_9_over.jpg", "");
	AddImageToImageList("rollover3", "images/header_11_normal.jpg", "images/header_11_over.jpg", "");
	AddImageToImageList("rollover4", "images/header_13_normal.jpg", "images/header_13_over.jpg", "");

function checkform(form)
{
	if (form.name.value == "") 
	{
	    alert( "Please enter your Name." );
		form.name.focus();
	    return false;
	}

	if (form.email.value == "") 
	{
	    alert( "Please enter your email address." );
		form.email.focus();
	    return false;
	}
	checkEmail = form.email.value;
	if ((checkEmail.indexOf('@') < 0) || ((checkEmail.charAt(checkEmail.length-4) != '.') && (checkEmail.charAt(checkEmail.length-3) != '.')))
	{
		alert("You have entered an invalid email address. Please try again.");
		form.email.select();
		return false;
	}

	if (form.code.value == "") 
	{
	    alert( "Please enter code." );
		form.code.focus();
	    return false;
	}
	return true;
}