Modifying effect display (effects package)

Hi,

I am using the effects package and plot() to produce an effect plot  
for a higher order term from a GLM. However, I need to modify the  
graph it produces by removing the tick marks and axes from the right  
and top of the graph, and moving the remaining tick marks inside the  
axes. Does anybody know how to do this? I can't find a way to modify  
the plot.

Thanks
Anna