для ИЕ
<html>
<head>
<script src="http://code.jquery.com/jquery-latest.js"></script>
<style>body {} </style>
</head>
<body>
<form>
<input type="password" id="fld4" name="pass" size="50" maxlength="80" />
</form>
<input id="a" type="button" class="button" value="Посмотреть" onclick="pas()" />
<script>
$("#a").click(function () {
var frm = $('form:first');
alert(frm.serializeArray()[0].value);
});
</script>
</body>
</html>