Default sans-serif font preference

Would it be possible to have system's default sans-serif be the default (rather than picking up verdana or lucida grande if available)?

i.e. (font-get-system-font) and (font-get-system-normal-font) for buffer-face variable width font, if in use....

[jonnay]

Lisp error: (void-function font-get-system-font)

font-get-system-font is only available on some emacs builds it seems?