Usage: last = priority [ [s] [l,bn,n,an] ] (single char argument)
old priority is returned in 'last', new priority
can be low, below-normal, normal, or above-normal.
pre-pending 's' to the priority string will cause
silent behaviour. priorities higher than above-normal
are returned as 'h', but cannot be set due to the risk
of freezing the machine. sending 'h' as the new priority
will set to above-normal.
Example: last = priority('sl'); % silen low % silen means no disp info
<do some idle processing>
priority(['s' last]);
Requires Win95 or WinNT 3.1 (or greater)