When I am using the DatePicker, jQuery's UI plugin, in an existing .aspx page I get errors that:
$("#datepicker").datepicker is not a function
However, when I copy and paste the same code that creates and uses the datePicker to an HTML file that's also in the same directory as the aspx page, it works flawlessly. This leads me to assume that there are some JS files in the aspx page that's preventing the datePicker or maybe jQuery's UI JS files from loading properly.
Can anyone confirm my beliefs or provide any tips on finding the culprit that's interfering with jQuery's UI plugins?