Changing the style properties?

[Felipe <felipito gmx net>]

Hi,

I want to remove the horizontal separators of a tree view, but the 
corresponding property is read only[1]. I assume that this style 
property can be changed in some way, but how?


Thanks in advance,



Felipe



[1] http://developer.gnome.org/doc/API/2.0/gtk/GtkTreeView.html#id3104240