Selezionare un campo di un form

[joule]

<form name="prevent">
<input type="hidden" name="C3" value="3">
<input type="hidden" name="SC3" value="2">
<input type="hidden" name="C12" value="11">
<input type="hidden" name="SC12" value="8">
<input type="hidden" name="C24" value="15">
<input type="hidden" name="SC24" value="12">
<input type="hidden" name="CDOPO" value="6">
<input type="hidden" name="SCDOPO" value="3">

<input type="hidden" id="BLUcop" name="BLUcop" value="60">
<input type="hidden" id="BLUscop" name="BLUscop" value="40">
<input type="hidden" id="BLUaggcop" name="BLUaggcop" value="9">
<input type="hidden" id="BLUaggscop" name="BLUaggscop" value="6">
<input type="hidden" id="BLUmin" name="BLUmin" value="168">
<input type="hidden" id="BLUmax" name="BLUmax" value="192">
<input type="hidden" id="BLUsconto" name="BLUsconto" value="20">
<input type="hidden" id="BLUtoll" name="BLUtoll" value="12">
<input type="hidden" id="VERDEcop" name="VERDEcop" value="55">
<input type="hidden" id="VERDEscop" name="VERDEscop" value="40">
<input type="hidden" id="VERDEaggcop" name="VERDEaggcop" value="9">
<input type="hidden" id="VERDEaggscop" name="VERDEaggscop" value="6">
<input type="hidden" id="VERDEmin" name="VERDEmin" value="168">
<input type="hidden" id="VERDEmax" name="VERDEmax" value="192">
<input type="hidden" id="VERDEsconto" name="VERDEsconto" value="20">
<input type="hidden" id="VERDEtoll" name="VERDEtoll" value="12">
<input type="hidden" id="ESTATE PARKINGcop" name="ESTATE PARKINGcop" value="65">

<input type="hidden" id="ESTATE PARKINGscop" name="ESTATE PARKINGscop" value="45">
<input type="hidden" id="ESTATE PARKINGaggcop" name="ESTATE PARKINGaggcop" value="10">
<input type="hidden" id="ESTATE PARKINGaggscop" name="ESTATE PARKINGaggscop" value="6">
<input type="hidden" id="ESTATE PARKINGmin" name="ESTATE PARKINGmin" value="168">
<input type="hidden" id="ESTATE PARKINGmax" name="ESTATE PARKINGmax" value="192">
<input type="hidden" id="ESTATE PARKINGsconto" name="ESTATE PARKINGsconto" value="20">
<input type="hidden" id="ESTATE PARKINGtoll" name="ESTATE PARKINGtoll" value="12">
<input type="hidden" id="INTERNETcop" name="INTERNETcop" value="70">
<input type="hidden" id="INTERNETscop" name="INTERNETscop" value="50">
<input type="hidden" id="INTERNETaggcop" name="INTERNETaggcop" value="10">
<input type="hidden" id="INTERNETaggscop" name="INTERNETaggscop" value="6">
<input type="hidden" id="INTERNETmin" name="INTERNETmin" value="168">
<input type="hidden" id="INTERNETmax" name="INTERNETmax" value="192">
<input type="hidden" id="INTERNETsconto" name="INTERNETsconto" value="20">
<input type="hidden" id="INTERNETtoll" name="INTERNETtoll" value="12">
</form>

<form name="2">
<select>
<option value="VERDE">Verde</option>
</select>
</form>

quando nel form 2 viene selezionato VERDE come valore avrei bisogno che mi apparisse un'alert che mi dice in valore del campo "VERDEmin" del form "prevent" ad esempio...

[floyd]

<select onchange="alert(document.prevent.elements[this.options[this.selectedIndex].value + 'min'].value)">
facile capire cosa fa