That works great too.  One more question now.  I would like a particular
MetaPost label to contain the value of a variable, say n.  I don't want to
use

label(decimal(n),origin);

because I want the label to be a TeX picture instead of a string.  That is,
I would like to have

label(btex n etex,origin);

where n is the VALUE of n and not the letter n.

Thanks,

Troy