To display a message on the Web page use Display a message on the Web page action.
This action is available at any event except JavaScript onload events.
Replace the text in the quotes with yours.
'********** Display a message on the Web page ************
MVCFunctions.Echo("Your message here")
See also:
•Grid Row JavaScript API: row.setMessage()
•AJAX helper object: setMessage()
•How to display messages or tooltips for the fields
•Change the 'Logged on as' message