Odp: comparing two columns of a dataset on a graph

hello

I want to compare the values of two columns of a dataset on a graph. 
Which graphic do you recommend ?

Hi Petr,
"barp" will compare the two columns displaying the values as heights of 
bars.

"stackpoly" will display superimposed polygons, the upper edges of which 
represent the data values in each column.

"twoord.plot" will dislay two data vectors as point/line plots even if 
they have different ranges.

All are in the plotrix package.

Jim