function readFromURL (strParamName, strDefaultValue) {
	
	// Reads the value of the URL parameter specified by strParamName. If not found, returns strDefaultValue.
	if (location.search.indexOf("?") == -1) return strDefaultValue;
	var arrParams = location.search.split("?")[1].split("&");
	if (arrParams) {
		for (i=0; i < arrParams.length; i++) {
			var param = arrParams[i].split("=");
			if (param[0].toLowerCase() == strParamName.toLowerCase()) {
				return param[1];
			}
		}
	}
	return strDefaultValue;
}
var menuItems = 6;
var navAlias      = new Array(menuItems);
var navLink       = new Array(menuItems);
var navImage      = new Array(menuItems);
var navImageOver  = new Array(menuItems);

navAlias[0]       = "home";
navLink[0]        = "home.htm";
navImage[0]       = "nav1.gif";
navImageOver[0]   = "nav1Over.gif";

navAlias[1]       = "books";
navLink[1]        = "books1.htm";
navImage[1]       = "nav2.gif";
navImageOver[1]   = "nav2Over.gif";

navAlias[2]       = "lectures";
navLink[2]        = "lectures1.htm";
navImage[2]       = "nav3.gif";
navImageOver[2]   = "nav3Over.gif";

navAlias[3]       = "biography";
navLink[3]        = "biography.htm";
navImage[3]       = "nav4.gif";
navImageOver[3]   = "nav4Over.gif";

navAlias[4]       = "latestnews";
navLink[4]        = "latestnews.htm";
navImage[4]       = "nav5.gif";
navImageOver[4]   = "nav5Over.gif";

navAlias[5]       = "contact";
navLink[5]        = "contact.htm";
navImage[5]       = "nav6.gif";
navImageOver[5]   = "nav6Over.gif";

nav = readFromURL("nav", "");

for (i=0;i<menuItems;i++){
	if (nav==navAlias[i]){
		document.write('<a  href="'+ navLink[i] +'?nav='+ navAlias[i] +'" title="" target="_top" onMouseOver="WM_imageSwap(\'myImg\', \'images/'+ navImageOver[i] +'\');" onMouseOut="WM_imageSwap(\'myImg\', \'images/'+ navImageOver[i] +'\');"><IMG SRC="images/'+ navImageOver[i] +'" BORDER="0" ALT="'+ navAlias[i] +'" name="myImg" hspace="20" vspace="10"></a><br>');
	} else {
		document.write('<a  href="'+ navLink[i] +'?nav='+ navAlias[i] +'" title="" target="_top" onMouseOver="WM_imageSwap(\'myImg\', \'images/'+ navImageOver[i] +'\');" onMouseOut="WM_imageSwap(\'myImg\', \'images/'+ navImage[i] +'\');"><IMG SRC="images/'+ navImage[i] +'" BORDER="0" ALT="'+ navAlias[i] +'" name="myImg" hspace="20" vspace="10"></a><br>');
	}
}