codice:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>
<head>
<title>Untitled</title>
<script language="JavaScript" type="text/javascript">
<!--
function controlla(textarea) {
 var f = richieste.value;
 //------ Rimpiazzare gli spazi
 f = f.replace(/\s*/gi,'');
 //------ Rimpiazzare gli a capo
 f = f.replace(/\x13\x10*/gi,''); 
 if (f != '') {
  alert(f);
 }
}
//-->
</script>

</head>
<body>
<textarea id="richieste" name="richieste" cols="50" rows="20"></textarea>

<input type="button" value="Clicca" onclick="controlla(richieste)"/>

</body>
</html>