[NTG-context] measuring alphabet length

Hi, I want to measure and typeset the lower case alphabet length. The LaTeX method doesn't work: \newlength{\alphabetlength} \settowidth{\alphabetlength}{abcdefghijklmnopqrstuvwxyz} \the\alphabetlength ConTeXt gives me an error saying that \newlength{...} is undefined. Is it undefined because ConTeXt is built around TeX and not LaTeX and \newlength is a LaTeX command (I do not know if it actually is)? How can I do the same thing in ConTeXt? Regards Christoph