Dataport Amend Unposted Sales Lines

Hi Everyone,

Version: NAV 2009 SP1
Database: SQL

I am trying to amend all the 'unit price' fields in the Sales Line Table. So I have created a dataport with Auto update and Auto Replace as YES.
The fields I am using for the Dataport are as follows:

Order Type
Document No.
Line No.
Unit Price

I have set the DataTableItemView to Order Type, Document No. & Line No.
The order lines already exist but when I run this dataport I get the following error.

You cannot enter 'Line No.' in Integer

Please help. I am not a developer!! I normally use dataports. Also I am testing this first, of course.

Thanks

ADARTIHS