codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<script type="text/javascript">
onload=function(){document.getElementById('mioID').className='sfumato';}
</script>
<style type="text/css">
.sfumato{
	opacity:0.6; 
	filter:alpha(opacity='60');
}
.normale{
	opacity:1.0; 
	filter:alpha(opacity='100');
}
</style>
</head>
<body>
<form name="frmContatti" >
<input type="text" id="mioID" name="mioID" value="Testo di prova" onfocus="this.className='normale'" onblur="this.className='sfumato'" />
</form>
</body>
</html>