In article <NW6X.1025$XG.12255955@harpo.ctel.net>, tobrey@moosehead.net says... > >I am trying to write an AF application that allows the user to enter values >into 3 variables(watcode($),year(n), and gear($)). The user may enter a value >in none, one, two, or all three variables. The SCL program will then create a >subset of an existing SAS dataset based on the user entered values. This >works fine if all three values are entered. However, if no year is entered, >there is no assignment made. I would have thought it would have been assigned >a missing value (.) as with other missing numeric values. So the problem is, >if I have a subsetting if statement: if yr=&year; And there is no value for >year it is translated as: if year=; This results in an error. I have tried >every imaginable combination to try to assign some kind of a value to a >non-existent value and I'm stumped. This seemed like a reasonably simple task >at the start(ha!,ha!) and perhaps I'm off the mark. Does anyone have any >advice for trying to create such a subset based on the 8 possible >permeatations of 3 variables (value entered or no value). TIA >

Thanks for all the help. I've got it working now. I tried the following in the SCL : if year ne _blank_ then do; but couldn't get it to work. I also checked under globals -->options--> missing--> and found that despite being set to . the AF variables still were left blank. The easiest way to solve the problem was to enter a . on the INITIAL field in the ATTR window. Also, I got it to work correctly by initializing the variables in the INIT: part of the SCL :

INIT: year=.; watcode=''; return;

Thanks again, Tim