[plug] Any way to repeat last search in emacs?

[David Buddrige]

Hi all, 

Using vi, if you press the "/" key, a search will be conducted for the
text that was searched for last... in this way, you can conviniently
jump through a text file to each occurence of a string, and make a
modification (manually) for each one, before pressing "/" again to jump
to the next string. 

Is there any way to do this in emacs?  I want to search for a particular
string that always occurs just prior to where I have to enter some
comments into my code, add the comment, and then jump to the next occurence
of the string.  However, once I have edited some text, I find I have to
enter the entire search string in again. 

Thanks in advance 

David Buddrige.