Editting a project

[ritfol]

I create some simple projects such as account classes or invoice classes from my school assignments and they seem to work perfectly and I save them.But I can't modify them later on.
When later I modify the source code files and compile the project again,it executes the previous saved project and the changes don't take effect even if I save after the modifications.I tried restarting CodeBlocks and compile but still,the changes don't take place.I looked for a solution in the internet and the forum but I couldn't seem to find one.
Is this normal,or is there something am doing wrong?..If yes,then how should I do it? ( modify my projects' source code file ).
Thank you.