/*
Title:		Preview Your Links with Unobtrusive JavaScript
Author: 	Chris Campbell
URL:		http://particletree.com/features/preview-your-links
Modified: 	7/27/2005
*/

addEvent(window, 'load', linkPreview);

function addEvent(obj, evType, fn){ 
	if (obj.addEventListener){ 
		obj.addEventListener(evType, fn, false); 
		return true; 
	} 
	else if (obj.attachEvent){ 
		var r = obj.attachEvent("on"+evType, fn); 
		return r; 
	}
	else { 
		return false; 
	} 
}

function linkPreview(){
	var links = document.getElementsByTagName("a");

	for (i=0; i<links.length; i++){
		var currentLink = links[i];
		var	images = currentLink.getElementsByTagName("img");

		if (images.length == 0){
			var linkHref = currentLink.href;

			if (linkHref.match(/amazon.com/)){
				append(currentLink, "amazon");
			}
			else{
				checkLinks(linkHref, currentLink)
			}
		}
	}
}

function checkLinks(linkHref, currentLink){
	var linkHrefParts = linkHref.split(".");

	var extension = linkHrefParts[linkHrefParts.length - 1];

	extension = extension.replace("/","");

	if( extension in { doc:1, pdf:1, ppt:1, txt:1, xls:1, zip:1 } ){
		append(currentLink, extension );
	}
}

function append(currentLink, extension){
	var span = document.createElement('span');
	span.innerHTML = "&nbsp;";
	currentLink.parentNode.insertBefore(span,currentLink.nextSibling);
	span.className = extension;
}