Microsoft JScript runtime error: Object doesn't support this property or method

Microsoft JScript runtime error: Object doesn't support this property or method

hi

when i want use Ui in my Project this error happen :

Microsoft JScript runtime error: Object doesn't support this property or method

i just copy and past sample code  in my project.

in my project i had a Default page, and some  user Controls. i want add ui in user control, and i add js file in default.aspx, but this error happen