# WriteMessage

Writes a text string over a Native Mode connection whenever the spreadsheet updates. WriteMessage outputs the string over the same connection as the ReadMessage tool.

Note: Insert a ReadMessage function in the spreadsheet to establish the Native Mode connection.

## WriteMessage Inputs

WriteMessage(Event,String)

Parameter | Description
--- | ---
Event | An external event that forces an update. This parameter must be a reference to one of the following: The Image data structure in cell A0, containing the AcquireImage function. For more information, see AcquireImage. A cell containing an Event function. For more information, see Event. A cell containing a Button function. For more information, see Button.
String | A string, or a reference to a cell containing a string.

## WriteMessage Outputs

Returns | A Message data structure containing the string to write, or #ERR if the input String value is invalid.