function buy($isbn){ //buy from Amazon using 10 or 13 digit ISBNs
	$tag='valerwildi-21';
	$re=/-/g;  //the regular expression to remove hyphens
	$isbnraw=$isbn.replace($re,"");
			
	$amazonlink="";
	if ($isbnraw.length==10){//traditional
		$amazonlink="http://www.Amazon.co.uk/exec/obidos/ASIN/" + $isbnraw + "/" + $tag ;
		}
	else  {//13 digit means look it up in amazon
		$amazonlink="http://www.amazon.co.uk/gp/search?keywords=" + $isbnraw + "&index=books&linkCode=qs&tag=" + $tag ;
					
	}
	am=window.open($amazonlink, 'amazon');
	am.focus()
}

function email(a,b){
	document.location = "mailto:" + a + "\x40" + b;
}

function email2(addr){
	//addr is the address with a @ sign replaced by an image
	//find the first <
	str=addr.innerHTML
	//alert (str)
	bit=str.split(/[<>]/)
	a=bit[0]
	b=bit[2]
	document.location = "mailto:" + a + "\x40" + b;
}