[HTML] pobierz, plaintext 
<form name="doublecombo">
<p><select name="example" size="1" onChange="redirect(this.options.selectedIndex)">
<option>kategoria 1</option>
<option>kategoria 2</option>
<option>kategoria 3</option>
</select>
<select name="stage2" size="1">
<option value="1">podkat1</option>
<option value="2">podkat 2</option>
<option value="3">podakt 3</option>
</select>
<input type="button" name="test" value="Wczytaj!"
onClick="go()">
</p>
 
<script>
<!--
 
/*
Double Combo Script Credit
By Website Abstraction (www.wsabstract.com)
Over 200+ free JavaScripts here!
*/
 
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("nazwa 1","1")
group[0][1]=new Option("nazwa 2","2")
group[0][2]=new Option("nazwa 3","3")
 
group[1][0]=new Option("nazwa 4","4")
group[1][1]=new Option("nazwa 5","5")
 
group[2][0]=new Option("nazwa 6","6")
group[2][1]=new Option("nazwa 7","7")
group[2][2]=new Option("nazwa 8","8")
 
 
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>
[HTML] pobierz, plaintext