Hi,
I need to update a field (not required) to null but I'm getting an invalid field error from the debugger when trying to save:

List<monthly_summary__c> MSUp = [Select Id, Billing__c from monthly_summary__c where Id IN : ListMSDelId];

                for(monthly_summary__c MSUp2 : MSUp) {
                    MSUp2.setFieldsToNull = new string[] { 'billing__c' };
//                    MSUp2.Billing__c = null;
                }
update MSUp;

Any suggestions?  I coundn't find much in the way of sample code to do this.
Thanks

Hello,

Can anyone help me in sending file from Salesforce to external file server, through REST? I'm struck with multi part form data! Any idea?