Position fungerar ej i forefox.

Någon som kan se varför följande css ej fungerar i firefox?

<style type="text/css"><!--
.1 {width: 30px; Height: 20px; position: absolute; left: 500px; top: 200px;}
.4 {width: 10px; Height: 10px; position: absolute; left: 150px; top: 150px;}
.9 {width: 50px; Height: 20px; position: absolute; left: 300px; top: 50px;}
.8 {width: 30px; Height: 20px; position: absolute; left: 400px; top: 00px;}
.10 {width: 20px; Height: 20px; position: absolute; left: 600px; top: 150px;}
.11 {width: 40px; Height: 30px; position: absolute; left: 200px; top: 100px;}
.12 {width: 70px; Height: 10px; position: absolute; left: 400px; top: 100px;}
--></style>

sedan använder jag t.ex <img src="apa.gif" class="1"><img src="apa.gif" class="4">

men bilderna hamnar direkt efter varandra.

den gillade visst inte att man numrerade sådär.. funkar om jag döper dom till a1, a4 osv.

In CSS2, identifiers (including element names, classes, and IDs in selectors) can contain only the characters [A-Za-z0-9] and ISO 10646 characters 161 and higher, plus the hyphen (-); they cannot start with a hyphen or a digit.

http://www.w3.org/TR/REC-CSS2/syndata.html#q4