codice:
<html>
<head>
<script type="text/javascript" language="JavaScript">
<!--
function control( __objForm )
{
if ( !__objForm.elements['Password'].value.length )
{
alert( "Inserire la password." );
__objForm.elements['Password'].select( );
__objForm.elements['Password'].focus( );
return false;
}
else if ( !(/^\d{5}$/).test( __objForm.elements['Password'].value ) )
{
alert( "La password deve essere di 5 cifre." );
__objForm.elements['Password'].select( );
__objForm.elements['Password'].focus( );
return false;
}
else
return true;
}
//-->
</script>
</head>
<body>
<form onsubmit=" return control( this ); ">
<input type="text" maxlength="5" name="Password" /> <input type="submit" />
</form>
</body>
</html>