.CONTINUE - Continues execution of a stopped program.
.SKIP - Skip over the next statement or statements.
.STEP - Executes one or more statements.
.STEPOVER - Executes one or more statements but do not step into routines.
.TRACE - Continue execution, display each line of code as it is executed.
BREAKPOINT - Set and clear breakpoints for debugging.
CODE_COVERAGE - Return line numbers of executed and un-executed code within a routine.
PROFILER -Analyze the performance of IDL code.
SHMDEBUG - Print debugging information for shared memory segments.
STOP - Halt the execution of a running program or batch file.