function navg(s1, s2)
{
 if (parent.frames[0]){
 theList = parent.frames[0].document.lists;
 if (theList!=null) {
 if (theList.length > 0) {
 if (theList[1].visible!=s1)
 { theList[1].visible = s1; theList[theList[1].pid].rebuild(); }
 if (theList[2].visible!=s2)
 { theList[2].visible = s2; theList[theList[2].pid].rebuild(); } } } }
}