Buffer size needed for PostThreadMessage()

Anyone know how I find out the message buffer size for a thread and if can this be changed or the queue size be monitored. Also, if this limit is exceeded are new messages ignored or are old ones deleted ?
Cheers
Jon

[RajM]

There used to be a function called SetMessageQueue
which lets u delete the current queue and recreate a new queue with the size u give.Its obsolete now in 32 bit windows.In 32 bit windows,the size of the message queues are managed dynamically by the system according to the documentation.