[R] How to add a variable to a dataframe whose values are conditional upon the values of an existing variable

[Steve Matco]

Hi everyone,

I am at my wits end with what I believe would be considered simple by a more experienced R user. I want to know how to add a variable to a dataframe whose values are conditional on the values of an existing variable. I can't seem to make an ifelse statement work for my situation. The existing variable in my dataframe is a character variable named DOW which contains abbreviated day names (SAT, SUN, MON.....FRI). I want to add a numerical variable named DOW1 to my dataframe that will take on the value 1 if DOW equals "SAT", 2 if DOW equals "SUN", 3 if DOW equals "MON",.....,7 if DOW equals "FRI". 
I  know this must be a simple problem but I have searched everywhere and tried everything I could think of. Any help would be greatly appreciated.

Thank you,

Mike