Updating another form onSuccess

Updating another form onSuccess

Hi,

This is my application:

hxxp://creator.zoho.com/anthonygemmill/function-testing/form/38/

This Contact form, under the OnSuccess event, tries to update a field in my Sales form i.e.

s = Sales [Project_ID == input.SYSTEM];
if (s.Company != null)
{
input.Company = s.Company;
}

However, once the form has submitted (using P4 for SYSTEM) the following error is shown and the Sales form update never occurs.

Error details:
Error occured while executing on success script.
Unable to update data on the form variable null
Error Occured in process

The field being updated is a picklist if that is any help. I have shared this application to support.

Many Thanks