my window disappears quickly

[Abeer]

Hi everyone..

I have problem in my project..
look at this first:
in dialog3.cpp

void Dialog3::openD4()
{
      drawGraph g;
    g.show();
}

void Dialog3::openD4()
{
      drawGraph g;
    g.show();
}

To copy to clipboard, switch view to plain text mode 

I have drawGraph.h , drawGraph.cpp ,and drawGraph.ui files
( I draw circles and add bottons inside it)
I call them window by define object and call show functon to display it after dialog3..

but it disappears quickly
so, I cann't see it!

when I call it in main.cpp,it doesn't disappear!!

anyone have idea about that?