Method that adds a new message at the current level in the message tree.
| Name | Type | Description |
| Message | String | Input String that specifies the error or warning message. |
| Error | Boolean | Input Boolean that specifies whether this is an error or a warning. True indicates error. |
| Reserved | Variant | Optional input Variant reserved for future use. Currently unused. This is an optional argument whose default value is null. |
| Name | Description |
| Display custom error messages | Demonstrates displaying custom error messages. |