Enabling building warning and error messages ?

[Plazzmex]

How to enable the warning and error messages like in Wx-DevCpp ?
for example in my code I have this line of code:
"static HWND hAllGroupBox;" and iI don't use it nowhere..
so Devcpp write me a message like this: "Warning: hAllGroupBox might be used uninitialized in this function" or something like this (don't remember the exact text)...
How can I enable thos messages in Code::Blocks ?
thanks..

Using Code::Blocks 8.02 with MinGW GCC Compiler on Windows XP.

[Ceniza]

In your project's build options, tab Compiler Flags be sure to enable Enable all compiler warnings (overrides every other setting) [-Wall]. If that doesn't do the trick, it might be a difference in the compiler version.

[Plazzmex]

It works.
I see the warnings when the compiler in the middle of the compiling.
but when the compile is finished, the warnings dissappear (I mean in the build log/build messages tabs there are no things written.), deleted. why ? I want that the build messages tab will remain the warnings after compile is finished