How to detrend data in Matlab2013a

Hello, I type 'det_s=detrend(s);'but I get a warning saying Error using detrend (line 24) Wrong # of arguments to detrend. Please how do I do it?

[dpb]

Looks like you've probably aliased the builtin detrend function...

What do the commands

which detrend
whos detrend

return?

Try

clear detrend

then try the function again...