SendAPMessage is available since version 1.0.
Prototype:
number SendAPMessage(number nToAPID, number nMSG_ID, string szData)
Parameters
nToAPID
[in] the APID of the target application that will have to call
GetAPMessage.
nMSG_ID
[in] the number part of a message
szData
[in] the string part of the message
Description:
Sends a message to another instantiated application. Message IDs in the range -1 .. -0x200 are RESERVED for the debugger, and should NEVER BE USED.
Return value:
Returns the size in bytes of the message. If 0, then an error was encountered.