Netscape 7 Not Finding Document.layers

I've tried to look for document.layers in Netscape 7 and couldn't get it... Here's the script:

Code:

var NS6 = (document.layers) ? 1 : 0;
var IE = (document.all) ? 1 : 0;
function bananas() {
if (IE)
alert("this is IE");
else if (NS6)
alert("this is NS6");
else
alert("bananas");
}

I'm only concerned with IE 5.5 or higher, and Netscape 6.2 or higher. In IE, it gives me the right stuff. But in Netscape 7 it gives me "bananas" (I haven't tried in Netscape 6.2) Why doesn't it work?