Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
   String[] toAddresses = new String[]{'theDoctor@who.com'};
   mail.setToAddresses(toAddresses);
   mail.setUseSignature(this.useSig);
   mail.setSaveAsActivity(this.saveActivity);
   mail.setSenderDisplayName(this.senderDisplayName);
   mail.setTargetObjectId(targetObjectId);
   mail.setTemplateId(templateId);
   Messaging.sendEmail(new Messaging.SingleEmailMessage[] {mail});
