tabs in the modal dont show up

what i am missing?
I have an accordian with links which show a modal dialog, the modal
dialog should have a tab menu. The dialog is full html page with head
having requierd tab data (initialization).
When i see the same page, separetly, tabs show up. but when the same
page show up in the modal dialog, only <ul>--</ul> shows....
Kindly some one explain or tell some solution.