[ale] sed help

[Robert Coggins]

OK all I hate asking questions like this on here but here we go.

I have a series of files. In each of the files there are many lines that 
only have ,,,,, on them.  For every line I find in these files I want to 
bring the previous line, the ,,,,, line and the next line together.

Example:

21321asdf2d6f5
,,,,,
fdsdhfksd6df5+sdf

seded to :


21321asdf2d6f5,,,,,fdsdhfksd6df5+sdf

Here is what I am trying but it is not working...
sed "s/\n,,,,,\n/,,,,,/g

Thanks in advance for your help!