How to update key fields???

I have created a table ztable with fields field1,field2,field3,field4,field5,field6.

the key fields are field1,field2,field3,field4,field5.

Records in ztable:

FIELD1 FIELD2 FIELD3 FIELD4 FIELD5 FIELD6

1 2 3 4 5 6

1 2 3 5 6 7

now i want to modify 1st row with field4 = 9.

and second row with field 4 = 10.

Please suggest how can i update field4.

since field 4 is a key field new line are inserted .

FIELD1 FIELD2 FIELD3 FIELD4 FIELD5 FIELD6

1 2 3 4 5 6 ....................................old

1 2 3 5 6 7................................old

1 2 3 9 5 6..............................new

1 2 3 9 6 7.............................new

Could anyone help me with a soultion.

Regards,

Rachel

Edited by: Rachel@sap on Dec 30, 2010 6:10 AM