If this is the same error from your initial post, try the following:

      (i) ls()                                        # look for an object
named Regression
      (ii) if ((i) is TRUE)   str(Regession)

Assuming you're getting the same error you reported in your initial post,
either the data object Regression is not present in your current workspace,
which is why I suggest starting with ls(), and if it is, str(Regression)
will summarize its contents. For example, str(Regression) will indicate the
type of object [rlm expects a data frame], its variables and the
corresponding types of those variables.

str() is also useful in that it tells you the names of the variables, which
you can match against the code in your model formula. Is it possible that
the offending variable name in the model is not a variable name in
Regression? Since R is a case-sensitive language, it matters whether the
names are capitalized or not.

HTH,
Dennis

On Tue, Sep 21, 2010 at 8:26 AM, uttara_n <nilawar.uttara@gmail.com> wrote:

>
> Hello Joshua,
>
> It still gives me the same error.
>
> Uttara
> --
> View this message in context:
> http://r.789695.n4.nabble.com/Error-in-eval-expr-envir-enclos-tp2547917p2548861.html
> Sent from the R help mailing list archive at Nabble.com.
>
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