I have read Freddy's blog post regarding creating and updating Sales Orders via web services but I have a question about how you do this if the order already exists.
The process to update lines seems to be to create them and then update the immediately, which is reality is not how this would work. Instead I want to retrieve the line, update a property on it and then call Update to save the changes.
The problem is in the retrieving, I don't have the key to search for and the page does not expose the Line No. field as a property to view in the array of sales lines. The only way from Freddy's post is to know the array index, but I only have the line number to use.
Any ideas?