Grouping fields of the internal table

hi all,

i ' m using an internal table, and y need to group fields like the following example:

what i have:

werks arbpl aufnr

ca01 ka mecha 1

ca01 ka mecha 1

ca01 ka li 1

ca01 ka li 1

what i need:

werks arbpl aufnr

ca01 ka mecha 2

ca01 ka li 2

can anyone help me?

Regards,

Roxana.