The
FileUpload
control is rendered as
<input type="file" />
So it will be always like a
TextBox + Button. CSS cannot change the basic look of a control.
The only way I see to achieve the requirement is:
You need to use
ActiveX controls
and Javascript to popup a
FileDialogBox
on click of the button and get the selected file name.
I am not very sure if this would be all.
You may search Google for "opening file dialog using javascript"
You may also take some help from this CodeProject article:
An Open File Dialog in JavaScript[
^]
Hope it gives you a good start for your research.