How to save project file in our own extension?

[arunpk]

I am new to Qt..I am working on a project in which i can open several files which will open new windows...
whenever i close these window it will ask to SAVE the project...I need to save these project files with my own extension(*.pot)...
my file will be containing one "icon editor" and one "scribble area". Whenever i open this file again for editing it should the previous
changes made on that file.
can anyone help me.........
I tried with QSettings....But it working fine with geometry and states..........i want to know how can i use it to save my icon editor and scribble area status.
(Both are of image type only..);

[ChrisW67]

You can call the files anything you like when you write anything you need to preserve the document into the file. What exactly is the problem?