I am having problems in getting Netscape 6 to hide/show a layer (div section) using javascript.

What I have been trying is

function showme(blah) {
if (is_msie) {
obj = document.getElementById(you[blah].title);
obj.style.visibility = "visible";
};
if (is_nav) {
eval("document." + you[blah].title + ".visibility = 'visible'");
};
}

though this just makes netscape complaining about document.layername having no properties.

If you could please help me out here it would be good as this is realy puzzling me.