I am trying to introduce a discrete change in the inflation rate with excel's if function but i dont know how to do it in excel. i've tried number of times but still cant get it to work, i am not familiar with excel.

please help!

many thanks

[NEAS: Post your cell function in the discussion forum so we can see what you wrote.  The Excel IF function is not difficult.  This function has a TRUE and a FALSE section.  Read the on-line help first.]