sorry for the late response

this is my sample data

Customer Key Customer no cust dt

------------ ----------- -------

50071000000000000 6328800 20070925

50070300000000000 6328800 20071105

50070900000000000 6328820 00000000

50070300000000000 6328820 20070507

50080500000000000 6328830 20080314

50071100000000000 6328840 00000000

50070300000000000 6328840 20080527

50071100000000000 6328860 19790523

50070500000000000 6328860 19900925

50070300000000000 6328870 00000000

thanks

vasu