[BioC] Creating an exprSet from two comma deliminated text files

[John E. Cornell, Ph.D.]

Dear Bioconductor List:

I have a set of 2-D gel protein expression data stored in an excel
spreedsheet.  I created two comma delimited texte files from the excel
spreadsheet: 1. phenoData with group names and covariate information and 2.
expression data.  I used the read.table function to create two data.frames
in R: xxCov and xxData.  I tried to use the new() function to create a
"phenoData" object from the xxCov and a vector covN with varLabels.  I get
an error message "Invalid 'phenoData' object: FALSE".  Queries for class()
show both xxCov and xxData are data.frame objects.  Is there some
intermediate step I need to convert the data.frames to some other object?
Keep in mind I am a novice R user.  I am using R 1.8.1 with the latest
Bioconductor release.

Thank you,

John Cornell