PropertyListBox.CustomGridLinesHorizontal
From Jeremie Leroy - XOJO Controls Wiki
Property (As Integer)
aPropertyListBox.CustomGridLinesHorizontal = newValue
or
IntegerValue = aPropertyListBox.CustomGridLinesHorizontal
or
IntegerValue = aPropertyListBox.CustomGridLinesHorizontal
Uses the Listbox GridLines constants See [1] for more information