There is a requirement to update ref_num as and when end user changes the type field value(want to give to analyst) values Incident, Problem, Request in Cr object.
So I have used Spell macro with trigger on update of type field.
I have used function 'send_wait(0, this, "call_attr", "ref_num", "set_val", varref_num, "SURE_SET");
Currently, we are prefixing the IN for incident and SR for Request, as and when user change the type field from incident to request, we need to change the IN to SR. I have used the function gsub for replacing IN to SR or viceversa.
But I am getting error "Error setting 'Can't modify attr after initial check in' " on changing the type value from drop down in CR object forms i.e. Incident, Problem, Request. like System not allowing us to update the ref_num using send_wait function.