variable scope

Hi ya, ok this is my little problem. You know how IE and netscape have diffrent objects for layers? So I made a simple little function based on what browser someone was using. The problem is variable scope I guess. Here's the code:

var layertype="null";

function find(){
if (navigator.appName == "Netscape") {
layertype="document.layer" }
else {
layertype="layer.style.";
}
}

I tried using this for my layers but I always get "laytertype" to come as "null". I even inserted a piece of code that wrote what the app name was once the function got called and it gave me the correct browser name.

Any help in this would be appreciated.