how to change indentation width in table of contents

[Oliver Redner]

Hi!

In documentstyle report I changed the chapter numbering from arabic to
roman. Now the width for the chapter number in the table of contents is
too small, chapter number and title of the chapter are almost printed on
top of each other (e.g.: "IIIThis is the title").
How can I change the width for each indentation in the TOC in general?

Please answer (also) by email!

Thanks, Oliver