Javascript Mutable Parameter?
function NamedItem(name)
{
    name = 5;

    this.getName = function ()
    {
        return name;
    }
}


document.write(namedItem.getName() + "n");  //5

function NamedItem(name) {
    this._name = name
}

NamedItem.prototype.getName = function() {
    return this._name
}