Laying out a dialog with a plot

I am new of Qwt and I wonder how to layout a QwtPlot and 2 vertical slider in a HBoxLayout

Something like this:
http://img219.imageshack.us/img219/9529/esempiov.jpg

Do I need to use QFrame or something else?

thanks

You can simply use QHBoxLayout. Global informations about how Qt uses layouts you can find here.