This is my first post here, happy

I am naive to LaTeX,so I am sorry if my question sounds silly.
I am writing a report and got a problem with chaptering and sectioning. I use the following command to define chapters, sections and so on:
\chapter{blablabla}
\section{blablabla}
\subsection{blablabla}
Now the problem is that chapter numbering appears fine in the main body and in the TOC but section and subsection does not. The counter is reset for those. For example what appears in chapter 2 in the main body and the TOC is this:
Chapetr 2 Background concept
1 background concept
1.1 brain and its function
1.2 different techniques in brain stimulation
1.2.1 DBS
1.2.2 TMS
and so on.But this is not what I want, I want like this:
Chapter 2 Background concept
2 background concept
2.1 brain and its function
2.2 differen techniques in barain stimulation
2.2.1 DBS
2.2.2 TMS
and so on.
I appreciate for your help. Thank you.[url][/url]