exit,stop,check,continou,reject

I think this is not the correct answer

control break statements in abap r

1. AT NEW f. 
2. AT END OF f. 
3. AT FIRST. 
4. AT LAST. 

these r with internal tables.....

No Naveen,
She is correct.

control break statements are :
check
exit
stop.

control break statements are of 4 types:

AT FIRST
AT NEW
AT END
AT LAST

AT FIRST---->this is used for system field heading in
              ABAP  program.

AT NEW------>this is used to display the fields.

AT END------>this is used for row-wise calculation i.e, 
             sub-total.

AT LAST----->this is used for calculation of grand total.


these are the control statements used.


hope this is right.

Priya answer is absolutely right , I faced this question in 
TCS Hyd.

AT First ===> Triggers in the first loop operation.
At New ===> Triggers when ever new field value changes at  
first.
At End Of ===> Triggers at the end of every field value.
At Last ===> Triggers in the last loop operation

one more control break statement is there that is 'ON 
CHANGE OF'.
can anybody tell the difference between ON CHANGE OF and AT 
NEW OF ?

@ Priya.
According to my one experience you can only use 'AT NEW'
with only the table's fields in which you are looping
whereas 'ON CHANGE OF' can be used with any data element
inside any table's loop.

Second 'ON CHANGE OF' is obsolete but as of my experience
'AT NEW' doesn't provide the same functionality.

Control break statements are
1. At First
2. At Last
3. At New
4. At End of 
And all these statements work only between Loop and Endloop.

Example:
F1  F2 F3
1   A  B
1   B  C
2   C  A
3   D  E

here F1, F2 and F3 are the three fields 

if we apply the At New statement between these three fields
then the output would be
1 b c
2 c a
3 d e

Belo are some more diff. between AT NEW and ON CHANGE OF 
statement..
1) AT NEW checks all the values above it ..where as 
ON CHANGE OF cheks only that particular value

2) AT NEW can be used in only LOOP..ENDLOOP where as 
ON CAHNGE OF can be used in any looping ...e.g 
LOOP..ENDLOOP, DO..ENDDO, WHILE..ENDWHILE  etc.