HMSetFontSize
HMSetFontSize Set the font size used to display text in help balloons
#include <Balloons.h> Help Manager
short fontsize; the global font size
You can use the HMSetFontSize function to set the font size that is
currently used to display text in help balloons.
fontsize specifies the global font size for the Help Manager to use to
display text in help balloons. This sets the font size for help balloons
in all applications and software that display help balloons. Use this
function only with extreme caution; the choice of font size should
always be under the user's control.
Returns: an Error Code.
noErr (0) No error
memFullErr (-108) Not enough room in heap zone

Warning: If your application changes the font name or size, the change affects
all applications and software that display help balloons