codice:
<form name="form">
<select name="continente" onchange="if(this.options[this.selectedIndex].value!=''){document.getElementById('ContinenteSel').innerHTML=this.options[this.selectedIndex].text}else{document.getElementById('ContinenteSel').innerHTML=''}">
<option value="" selected="selected">Seleziona un continente:</option>
<option value="africa">Africa</option>
<option value="asia">Asia</option>
<option value="australia">Australia/Oceania</option>
<option value="europa">Europa</option>
<option value="noamer">Nord America</option>
<option value="suamer">Sud America</option>
</select>
<select name="città" onchange="if(this.options[this.selectedIndex].value!=''){document.getElementById('CittaSel').innerHTML=this.options[this.selectedIndex].text}else{document.getElementById('CittaSel').innerHTML=''}">
<option value="" selected="selected">Seleziona una città:</option>
<option value="pisa">Pisa</option>
<option value="firenze">Firenze</option>
<option value="palermo">Palermo</option>
<option value="marsala">Marsala</option>
<option value="livorno">Livorno</option>
<option value="newyork">NewYork</option>
</select>
</form>
Continente selezionato : <span id="ContinenteSel"></span>
Paese selezionato : <span id="CittaSel"></span>