Originariamente inviato da kurtdc
come devo fare?
Così:
codice:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<script type="text/javascript">
	function checkSelect(laSelect){
		if (laSelect.options[laSelect.options.selectedIndex].value == "4") {
			document.getElementById("idLabelTesto").style.display="";
		}
		else {
			document.getElementById("idLabelTesto").style.display="none";
		}
	}
</script>
<title>Test</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body>
<form name="test">
	<select id="idSelect" name="nameSelect" onchange="checkSelect(this)">
		<option value="" selected="selected">Scegli un valore ...</option>
		<option value="1">Valore uno</option>
		<option value="2">Valore due</option>
		<option value="3">Valore tre</option>
		<option value="4">Valore quattro..diverso</option>
		<option value="5">Valore cinque</option>
		<option value="6">Valore sei</option>
		<option value="7">Valore sette</option>
	</select>
	

	<label for="idTesto" id="idLabelTesto" style="display:none">Inserisci il valore per quattro...
	<input id="idTesto" name="nameTesto" type="text"/> 
	</label>
</form>
</body>
</html>
HTH
Zappa