DatePicker Validation

Hi

I am trying to use this code to perform validation on a DatePicker on dev2.electrixinternational.com/request-a-quote/

// CT Limit available date range in the checkout DatePicker
add_filter( 'wp_footer' , 'woo_add_checkout_field_date_range_limit' );
/**
 * woo_add_checkout_field_date_range_limit
 *
 * @access      public
 * @since       1.0 
 * @return      void
 * See: http://jqueryui.com/datepicker/#min-max
*/
function woo_add_checkout_field_date_range_limit() {
	if ( is_checkout() ) {
	?>
	<script type="text/javascript"> 
		jQuery( document ).ready( function ( e ) {
			jQuery(function() {
				jQuery( "#required_by_date_field" ).datepicker({ minDate: 1 });
			});
		});
	</script>
	<?php
	}
}

It isnt working – I am not sure if it is because I am not referencing the field correctly.

I basically want the field so someone can only select >= TODAY (they shouldnt pick a date in the past).

Does anyone have any suggestions?

Thanks