Controls screen updating while a macro is running
static int Echo( short int logical );
Logical is a logical value specifying whether screen updating is on or off. A value of -1 is treated as a missing argument, A value greater than 0 is treated as TRUE, and 0 is treated as FALSE.
Zero if the function has been called successfully; non-zero if the function could not be called. See Error codes for a list of return values.
See the Microsoft Excel on-line Help for full details about this function.