How to use a signal

["Jamiil Abduqadir" <jalqadir gmail com>]

Hey again folks, continuing with the my previous posting about handling Entry boxes empty, I am using

Glib::SignalProxy1< bool,GdkEventFocus* > Gtk::Widget::signal_focus_out_event()

to check when the user leaves the box empty, but I am getting some errors at compile time, can anyone help!!??

namespace jve{
Entry{
      .......
      Gtk::Entry* text_box;
public:
      MyClass();
      .........
      void onBlanck();
};
}
jve::Entry::Entry(){
      ....
      text_box  = Gtk::manage(new Gtk::Entry());
      text_box->signal_focus_out_event().connect(sigc::ptr_fun(&onBlank)); <== here is the problem
      ....
}
void jme::Entry::onBlank(){ // this->getText() returns a Gtk::ustring object
   if(this->getText(().empy()){
      // Display a Dialogbox explaining the problem
      text_box->grab_focus();
   }
}

D:\c++\entry.cpp||In member function `void jve::Entry::Entry()':|
D:\c++\entry.cpp|12|error: ISO C++ forbids taking the address of an unqualified or parenthesized non-static member function to form a pointer to member function.  Say `&jme::Entry::onBlank'|
D:\c++\entry.cpp|12|error: no matching function for call to `ptr_fun(void (jve::Entry::*)())'|
||=== Build finished: 2 errors, 0 warnings ===|


Thanks in advance
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