<form name="doublecombo">
<p><select name="example" size="1" onChange="redirect(this.options.selectedIndex)">
<option>1</option>
<option>3</option>
<option>10</option>
</select>

<span name="stage2">10
</span>
</p>

<script>
<!--
var groups=document.doublecombo.example.options.length
var group=new Array(groups)
for (i=0; i<groups; i++)
group[i]=new Array()

group[0][0]=new Option("dziesięć","10")

group[1][0]=new Option("dwadzieciapięć","25")

group[2][0]=new Option("sto","100")

var temp=document.doublecombo.stage2

function redirect(x){
for (m=temp.options.length-1;m>0;m--)
temp.options[m]=null
for (i=0;i<group[x].length;i++){
temp.options[i]=new Option(group[x][i].text,group[x][i].value)
}
temp.options[0].selected=true
}

function go(){
location=temp.options[temp.selectedIndex].value
}
//-->
</script>