Help about stability analysis in R software!!!

?

   Hello  people!! I'm trying to make a statistical analysis of stability
   through to package 'Agricolae', and procedure 'stability.par', but I don't
   get conclude the analysis. The problem is in my data set, that have missing
   value, and I didn't manage interpret the 'NA' used to assign missing value.
   Someone have any suggestion to solve the problem?
   I thank from now on!
   Regards,
   Lu?ce.