script browser-css

[motorcycle]

<script>
function bsniff(){

this.dom = document.getElementById?1:0;
this.ie = (document.all && !this.dom)?1:0;
this.IE = (this.dom && document.all)?1:0;
this.n4 = (document.layers && !this.dom)?1:0;
this.NN = (this.dom && !document.all)?1:0;
this.opera = window.opera?1:0;
return this;

bw = new bwsniff();

if(bw.ie){ ///se IE 4
document.write(prova.css)}

if(bw.IE){
document.write(prova2.css)}

if(bw.n4){
document.write(prova3.css)}

if(bw.NN){
document.write(prova4.css)}

if(bw.opera){
document.write(prova5.css)}

}</script>



è corretto?