<form name="f" id="f" method="POST"> 
 
<select id="kat" name="kat"> 
	<option value="" selected="selected">Wählen Sie eine Kategorie:</option> 
	<option value="">---------------------------------</option> 
	<option value="A">A</option> 
	<option value="B">B</option> 
	<option value="C">C</option> 
</select> 
 
<br /><br /> 
 
<input type="submit" id="submit" name="submit" value="Senden" /> 
 
</form> 
 
 
<script type="text/javascript"> 
 
document.getElementById("kat").onchange=function() { 
 
	var chosenoption = this.options[this.selectedIndex]; 
	resetOptions(); 
 
	if (chosenoption.value != "") { 
		chosenoption.style.backgroundColor="#660000"; 
		chosenoption.style.color="#ffffff"; 
	} 
 
} 
 
 
 
function resetOptions() { 
	var items = document.getElementById("kat").options.length; 
	for(k=0; k<items; k++) { 
		document.getElementById("kat").options[k].style.backgroundColor="#ffffff"; 
		document.getElementById("kat").options[k].style.color="#000000"; 
	} 
} 
 
</script>