Credit Limit issue

Hi

) For one customer master we have two operating Unit's and bill to's were also defined for both the operating Unit's

2) Credit Limit were given for each operating Unit

3)Now the requirement is instead of giving Credit limit at each customer site level for each operating Unit they want only one amount at the customer mater level.

4)I have removed the amount in Customer site level and given the amount at the customer Master level(Profile Amounts Tab)

I have given the Credit Limit at customer master level (900,000)

AR Balance Operating Unit 1 is 771,725.15
AR Balance Operating Unit 2 is 54,600.00

I have created and booked one order for 17,634 for operating unit 1