Uncaught TypeError: Cannot read property '_selectDate' of undefined

I’m getting this error

“Uncaught TypeError: Cannot read property ‘_selectDate’ of undefined”

Located here

//########################################################################
// the bad hack :/ override datepicker so it doesnt close on select
// inspired: http://stackoverflow.com/questions/1252512/jquery-datepicker-prevent-closing-picker-when-clicking-a-date/1762378#1762378
//########################################################################

// ERROR LINE
$.datepicker._base_selectDate = $.datepicker._selectDate;  
// END ERROR LINE

$.datepicker._selectDate = function (id, dateStr) {

This error appears to only happen in Google Chrome (v11.0.696.71)

[KKKKeZZZZ]

It’s kinda funny, because I import the datepicker js package before the jquery UI, this issue occured. When I change their order, problem solved.

[mortenporten]

I was trying to keep the jQueryUI to a minimal and must have deleted something that I should not have deleted. I downloaded the jQueryUI again and kept it all and now it works. Thank you for your time!