Comparing two internal tables

Hi all,

I have one internal table itab1 which has contents from legacy system. Now I have another internal table itab2 which has contents from a SAP standard table,i.e. AMPL. I have to compare the contents of these two tables i.e. itab1 and itab2 and add those entries to the AMPL table which are present in itab1 but not in itab2. I can explain it more if anyone helps me out here. Points assured.

Thanks.