MsgYesNoCancel()

Show a message box with "Yes,No,Cancel" buttons

SYNTAX

MsgYesNoCancel (<cMessage>,<cTitle>, [<nIcon>], [<lSysModal>], [<nDefaultButton>], [<lTopMost>]) --> nResponse

RETURN

nResponse ->    1   value if successful
0   value if Button No pressed
-1   value if Button Cancel pressed