Textbox width is automatically changed when using with AutoCompleteExtender

Hi all,

I have some Textboxes on my page, one of them using with AutoCompleteExtender. The first time, when I click (focus) on any Textbox, the width (and its CSS - border) of Textbox which is used for autocomplete is changed automatically, it's not the same with the other textboxes on my page.

I don't know what happen. Do you have any ideas about this ?

Thanks a lot,

Phuc PHAM