Get window (sheet) name (classname) and library in Powerbuilder

//below function were on clicked event of menu in a mdi...

window lw_active
string ls_winname, ls_libname, ls_wintitle
ClassDefinition cd_windef

lw_active = parentwindow.GetFirstSheet()

if isvalid(lw_active) = True then
        ls_winname = lw_active.classname()
       
        cd_windef = FindClassDefinition(ls_winname)
        ls_libname = cd_windef.LibraryName
        ls_wintitle = lw_active.title
       
        messagebox(ls_winname, ls_libname+'~r~n~r~n'+ls_wintitle, Information!)       
end if