prova questo:
codice:
<script type="text/javascript">
function sposta(v){
if(v){
var i = document.Form.opt.selectedIndex;
var s = document.Form.opt.options[i].text;
var p = 0;
for(p=0; p < document.Form.opts.length; p++){
if(document.Form.opts.options[p].text == "#"){
var x = document.Form.opts.options[p];
break;
}
}
x.text = s;
document.Form.opt.options[i].text = '#';
}else{
var i = document.Form.opts.selectedIndex;
var s = document.Form.opts.options[i].text;
var p = 0;
for(p=0; p < document.Form.opt.length; p++){
if(document.Form.opt.options[p].text == "#"){
var x = document.Form.opt.options[p];
break;
}
}
x.text = s;
document.Form.opts.options[i].text = '#';
}
}
function sposta2(v){
var i = document.Form.opts.selectedIndex;
var s = document.Form.opts.options[i].text;
if(v){
var ibis = i + 1;
var temp = document.Form.opts.options[ibis].text;
for(f=0; f < document.Form.opt.length; f++){
if(document.Form.opt.options[f].text == "#"){
document.Form.opt.options[f].text = temp;
break;
}
}
}else{
var ibis = i - 1;
var temp = document.Form.opts.options[ibis].text;
for(f=0; f < document.Form.opt.length; f++){
if(document.Form.opt.options[f].text == "#"){
document.Form.opt.options[f].text = temp;
break;
}
}
}
document.Form.opts.options[ibis].text = s;
document.Form.opts.options[i].text = document.Form.opt.options[f].text;
document.Form.opt.options[f].text = '#';
document.Form.opts.options[ibis].selected = 'true';
}
</script>
<form name="Form">
<SELECT NAME="opt" size="10">
<OPTION SELECTED> Pippo
<OPTION> Topolino
<OPTION> Paperino
<OPTION> Paperone
</SELECT>
<SELECT NAME="opts" size="10">
<OPTION SELECTED>#
<OPTION>#
<OPTION>#
<OPTION>#
</SELECT>
<input type="button" value="sposta ->" onclick="sposta(1)">
<input type="button" value="<- sposta" onclick="sposta(0)">
<input type="button" value="sposta su" onclick="sposta2(0)">
<input type="button" value="sposta giù" onclick="sposta2(1)">
</form>