sans serif (sub(sub(section)) title appearance [duplicate]

I want that all \section, \subsection & \subsubsection entries that appear in the resulting pdf file are displayed with a sans serif font. I already tried to redefine the \section command as follows: \renewcommand{\section{}}{\section{\textsf{}}}. Unfortionately, this doesn't format. The reason probably is that I don't pass the argument of \section. How can I define the redefinition correctly? Francky @Leyn.eu