JQuery :: Use Regex To Match A Value In Form Input?

I'm trying to create a branching form wherein the user selects a date using the datepicker plugin, then, depending on whether they choose a weekday or a Saturday, they are presented with one or the other of 2 select lists to choose the time.

I'm just getting started, and I can't seem to get the regex right. Here's a simplifed version of the relevant part of the datepicker,

$(function() {
$(".datepicker").datepicker({dateFormat: 'D, mm-dd-yy',buttonText: 'Click Me!', });
});

and here's the initial test to see if the chosen date falls on a weekday or a Saturday:

$(document).ready(function() {
$(':input[name=datepicker]').change(function() {
if ($(this).val()!=/^Sat,.*/)
{

[Code]....