In ASP.NET a number of controls are rendered with the '$' inside the element Id.

Ex.

<input type="text" id="txt$sample" class="datebox" />

I can use the following 3 valid selectors to display the datepicker box;

$('#txt\\\\$sample').datepicker();

$("input:text[id$='sample']").datepicker();

$('.datebox').datepicker();

All 3 of these will display the datepicker when the textbox receives focus, but when a date is selected an exception occurs.

Once the "$" is removed from the element id, the error goes away.