how to get minimum width of blind table

Hi,
I hope someone can help me with a tricky problem:

I programmed a blind table which is going to the instrument for a good
layout of my new website (it contains the whole content). Now I try to
configure the table that it has a difined minimum width (about 900 pixel)
but can grow wider if someones screen allows it. What shall I do?
I tried to solve this problem on many ways with the ordinary html-tags
"widht" for the whole table or/and the seperate cells but I couldn't find a
satisfying solution.
It would be great if someone out there could give me an advice!

Thanks,
Michel Weidner, Germany.