When I am trying to create a order in netsuite i am getting alert that "customer balance of 26000 exceeds the credit limit 25000" How can I disable this alert and allow the sales order to be proceed

Setup Accouting > Stay in General tab. Then Ignore as per my screenshot below. But as you already said, sounds like that is just an alert, so you can click OK and ignore it and proceed with the SO anyway

Thank you so much... I am creating a reject button on sales order when the order is in pending approval... and then and on the reject button click user is entring the rejection reason that i am storing in custom field and setting the approvalstatus field to rejected but the status is still pending approval