These statements are executed only with in Loop...................Endloop.
Control break statements are
AT FIRST - This statement is executed/triggered for the first iteration of loop (SY-TABIX = 1 ).
AT LAST - This statement is executed/triggered for the last iteration of loop.
AT NEW - This is executed whenever there is a new value on specified field.
AT END OF - This statement is executed whenever the new value ends on specific field.
ON CHANGE OF - It is same as AT NEW and is obsolete in ECC 6.0.
