Disabled code to validate "cannot be posted/approved because it would cause the cost budget to be exceeded"

Hy sir,

I have error message like this, when save Purchase Requisition :

“The entry for category ‘A03000000-I’ on project ‘AML.101.02’ cannot be posted/approved because it would cause the cost budget to be exceeded by 50,000,000.00.”

I want to remark this validate by code. Someone can show me, where is line code or method to validate this case?

Thanks,

Samuel