[R] Extract data from edit chart

[Chun-Ying Lee]

Dear R users:

I wonder if it is possible to use 
"data.frame" and "edit" to show the 
form like:

parameter   upper  lower
   A 
   B
   C
when I type the command edit(abc), assume
the data.frame named "abc". And then I want to 
extract the number form it, like abc[1,2] 
which mean the upper level of A, to do something.

The following is my example and the warning messages:
> abc<-data.frame(Parameter=c("a","b","c"),Lower=c(" ")
    ,Upper=c(" "))
> par<-edit(abc)
then, I key in some number(1,2,3...) and close the console.
Warning messages:
1: added factor levels in 'Lower' in: edit.data.frame(abc) 
2: added factor levels in 'Upper' in: edit.data.frame(abc) 
> par[1,2]
[1] 1
Levels:   1 2 3
How can I fix the warning messages?
And can I just catch the number 1 without the value of Levels: 1 2 3 ?
Please give me some comments about this.
Thank you in advance!!