(Gtk) Interface designed with GLADE, the registered function for button click event is not being called

[mantzaris]

using Gtk


function main()
    b = GtkBuilder(filename="try1.glade")
    win=b["mainWindow"]
    
    button=b["mainWindowButton"]
    signal_connect(simple,button,"clicked")
    
   showall(win)
end

function simple(Widget)
    println("clicked")
end

main()