Suppress call update emails?

I have the following in my BeforeSubmit script:

//Set Outgoing message to Original Email contents and add to ticket update log (Do not update customer)
var fields = new Array();var values = new Array();fields[0]='emailform';values[0] = "F";fields[1] = 'internalonly';values[1] = "T";fields[2] = 'outgoingmessage';values[2] = '[REPEAT BOUNCING ALERT]  \n' + emailMsg;var updatefields = nlapiSubmitField('supportcase', ticketID, fields, values);

This works well, and I can figure out how to change this to email the customer or not. However, I want to update the call with this entry, but not email the support team to notify them of the call update. In Support preferences, I have set to update the support team on any case update. How can I override this? Is there a field I can set using the above code?