sending GtkTreeSelection to other function

[Ranieri <ranieri_savage yahoo com br>]

how send a GtkTreeSelection *selection, to other function using 
g_signal_connect ?
Example:

void new_function(GtkTreeSelection **selection);

void main(int argc, char **argv)
{
   ...
   ...
   GtkTreeSelection *selection;
   ...
   ...
   ...
   g_signal_connect(G_OBJECT(button), "clicked", new_function, selection);
   ...
   ...
}

What this wrong in this source code ?

Thanks!