check if buffer exists

[Naim Far]

Hi all,

Could anyone help me with the command of checking if a certain buffer
exists, I wasn't to do something like the following

"
if( exists(<File Name) )  ;; a buffer exists
 b <File Name> ;; open the buffer
else
 find <File Name> ;; find such a file and open it
endif 
"

Thanx in advance...