Set default sort on Relationship view by item number

1. Went to the Itemtype definition for the relationship, Changed the Order By value for the definition of the Sequence property to 2.

I have done the following changes in my Aras 11 SP15. but when I open the form it still sorts on the basis of sequence but after refreshing it sorts on behalf of item number.

I tried OnBeforeGet method to change sort_order but it shows me Object object error.