Script to manage different types of thumbnails

[Lampe]

This Js is designed to help the user when choosing items in my personal portfolio.

Whats seem to be wrong?
Cheeck out the webpage on:
http://www.lampe.se/new/index.html

window.onload = initiera;

function initiera () {

showCat();
}

function showCat () {
	//FilterCategorier
	//-- WEB
	var catWebBtn = document.getElementById("webBtn")
	//-- PRINT
	var catPrintBtn = document.getElementById("printBtn");
	//-- 3D
	var cat3dBtn = document.getElementById("tredBtn");
	

	var catBtn = new Array();
	catBtn[0] = catWebBtn;
	catBtn[1] = catPrintBtn;
	catBtn[2] = cat3dBtn;


	for(var i = 0; i < catBtn.length; i++) {
		catBtn[i].onclick = function () {
			var catHit = this.getAttribute("id");
			alert(catHit);
			

			var thumbName = "thumbShadow"
			

			var thumb = document.getElementsByTagName("div").className = thumbName;
			alert(thumb.length); //Returns "11"? Should be "9".
		
			for (var j = 0; j < thumb.length; i++) {
				var currThumb = thumb[j];
				var currThumbTitle = currThumb.getAttribute("title");
				
				if(currThumbTitle != catHit) {
					currThumbTitle.style.display = "none";
				}
			}		
		}
	}
}

Thanks!

[Fang]

This doesn't work:

var thumb = document.getElementsByTagName("div").className = thumbName;

You're trying to find elements by className:

function findByClass(tagname, classname) {
var aObj=document.getElementsByTagName(tagname);
var i=aObj.length; 
var list=[];
while(i--) { 
    if(aObj[i].id.indexOf(classname)!=-1) {list.push(aObj[i]);}
    }
return list.reverse();
}

getElementsByClassName does exist, but is not supported in IE