The setFieldValue method sets the value of a field in a document. If the field does not exist, it is created. If the field already exists, the existing value is overwritten.
setFieldValue( fieldname, newvalue )
| Argument | Description | 
|---|---|
| fieldname | (string) The name of the field to set. | 
| newvalue | (string) The value to set for the field. | 
|  |