[R] grid lines when plotting its object

[M. Sutter]

Dear R community

When plotting an its object (with 'plot(..)), grid lines are 
automatically added which I cannot control with parameter 'tck/tcl'.
Furthermore the vertical grid lines (time axis) do not comply with the 
automatically generated tickmark locations.

Can somebody tell me how to handle these grid lines ?
How can I switch off the grid lines ?

Thanks a lot for any advice and I'd like to thank all the R 
developpers/experts for spending their precious time answering questions 
on the r-help mailing list and making it very valuable for R users like me.

Package: its
Version: 0.2.2
Date: 2004/01/06

 > version
         _               
platform i686-pc-linux-gnu
arch     i686            
os       linux-gnu       
system   i686, linux-gnu 
status                   
major    1               
minor    8.1              --> I know, 9.1 is released ... I 
suppose/hope, thats not the problem
year     2003            
month    11              
day      21              
language R               
 >