Working on several projects - m-files each in a separate folder - needs the knowledge about the current folder in the search path. IsPath checks for user specific folder(s) in the search path.
p = IsPath(<foldername>); %returns true or false
p = IsPath; %returns a string with all user specific path(s). Can be used by rmpath(p) to remove all specific path definitions
@Evgeny: Using (sulking)camel-case for user defined functions has a great advantage: If someone reads the code, it is obvious, if a certain function is user-defined or a toolbox function of Matlab -- but e.g. RandStream is not lower case also.