Sales Order status still open after create a new sales order with reference

Hi Experts,

We create an inquiry, quotation and Indent sales order (Ex.SO no. 123) than we created a new DMR sales order with reference indent sales order(SO: 123) and created a Debit memo with reference DMR sales order. all the documents like DMR sales order, Inquiry, Quotation and debit memo status is completed but Indent sales order status is open.

Please suggest me how indent sales order's status can be changed as complete automatically in above scenario.

Thanks in advance.

Shatrughan