\makebox[width][position]{text}
The \makebox command creates a box just wide enough to contain
the text specified. The width of the box is specified by the
optional width argument. The position of the text within the box
is determined by the optional position argument.
c -- centred (default)
l -- flushleft
r -- flushright
s -- stretch from left to right margin. The text must contain
stretchable space for this to work.
See section \makebox.