I seem to remember that Dev doesn't like long directory names. So try creating a new folder with a bit shorter name. (C:\project)
Put the files in the new folder and create the new project in that folder. Then try again.
to Vernon : I am very appriciative for your help
I tried to create a new project and add 3 stuff like you said,
but the same problem still occur. you can see on the screen ?? I take the photos and post it for you.
In Dev C++, right click on each file and select "Remove File". Then for each file, right click on "Project1" and click "Add To Project" then click on the file. To be safe, make sure all four files (.cpp files, .h file, .dev file) are in the same directory. Make sure the file is really named draw.h. If not, rename it. If you have more than one version of something, delete the old files. Doing the above will make sure the project file knows where everything is, thus removing all doubt regarding paths and capitalization.