Trouble with function to update field with current date via custom action

Trouble with function to update field with current date via custom action

The custom action button in my report runs and displays the  success message.
However when I check the Quote Sent Date field it is empty.

Here is my function code

void SentRFQ()
{
    rec  =  RFQ  [ID == ID];
    rec.Quote_Sent_Date = zoho.currentdate;
}

Any ideas