This option lists the font sizes which appear in the "Size" toobar combo. By default, the following values are available:

FCKConfig.FontSizes = 'smaller;larger;xx-small;x-small;small;medium;large;x-large;xx-large' ;

You may use any valid CSS compatible value for it. The following example set pixel, relative and percent sizes:

FCKConfig.FontSizes = '14px;1.5em;80%' ;

A name can also be set for each size, which is displayed in the combo instead of the raw size value. Just separate the size and the name with a slash. For example:

FCKConfig.FontSizes = '14px/Fourteen Pixels;1.5em/A bit biggger;80%/A bit smaller' ;