how to increment column value by 1

hi in my table request i have columns as follows
requestid,applicationid,statusid,usertypeid & the data is
1,xxxxx, 1,6
2,xxxxx,2,7
3,xxxxx,3,8
i vil pass requestid to a storedprocedure , and i want to increment statusid,usertype by 1.
create procedure updateusertypeid_statusid
@requestid int
as
begin
update request set usertypeid += 1, statusid += 1 where requestid = @requestid.....this is not working
pls help me to implement this requirement