You can execute your program by using step commands or the Run command.
Step commands
The step commands are located in the tool bar of the source windows and under the Run menu of the source windows.
You can start the RUN command from the Run button in the tool bar or the Run menu of the source windows.
When you execute your program, a clock icon displays to indicate that the program is running and might require input to continue to the next breakpoint or termination of the program.