Schengen Visa

[immihelp]

Hi,

I am an Chinese exchange student in University of Manchester in the UK
and I am currently holding " UK tier 4 studnet visa" that is valid till
June 18, 2010. And I am still holding US. F1 visa which is valid till
December 20 2010 since I go to US for college education and my
nationality is Chinese.

And I am planing my trip to France to visit my friend there at early
March for a weekend and again during easters.

Based on that,
1. If I apply for visa in March, Would I able to enter France again if I
visit her in April? Do I need apply another schengen visa after my trip
to France in March? How long does a schengen visa valid for?

2. If I would like to travel in France in summer without ever returning
to the UK but back to US, do I need to extend my UK visa? I am doubting I don't need a visa since I am holding US F1 visa.

Thank you.

[immihelp]

1. That depends upon whether you get single or multiple entry visa and for
how long that visa is valid.
2. I am not sure about UK visa rules.