tengo ete script
<script language="JavaScript">
if (screen.width + "x" +screen.height == "640x480") location.href="pagina640x480.htm"
if (screen.width + "x" +screen.height == "800x600") location.href="pagina800x600.htm"
if (screen.width + "x" +screen.height == "1024x768") location.href="pagina1024x768.htm"
</script>
y quiero segun si es resolucion 640x480 que escriba dentro del form esto
<input type="hidenn" value="valor_de_la_resolucion">
se puede?