Check limit in Financial and Sales order

Dear All Expert,

Please advice me on below tasks:

1. I have create sales order as value USD5,000.00

2. Than created a financial docs# 42 as value also 5,000.00 USD

Again I made changed the value in sales order as USD10,000.00

My requirement is when I made change into Sales order qty/value or add new item it should not overflow the amount from financial value(L/C).

How can I block the check limit when the value is overflow?

Thanks in advance

With B/R

Bishnu

02.06.2013