BAPI_salesorder_createfromdat2 bapi error

Dear gurus

I tried to create the sales order through bapi.

In that if i mentioned the document type OR,it couldnt create the order.

But if i use TA (which is the sales order type in german language for OR) ,then it creates the order.

What will i do to create the order by passing the value as OR in document type.

Kindly advise me.