imap_fetchbody parts problem

Hi all! I have a problem with specification of parts of message in command imap_fetchbody. About the last parametter is written: "The section specification is a string of integers delimited by period which index into a body part list as per the IMAP4 specification." (PHP manual) What is in fact "period" in this sentence? There are no problems, if I want to fetch first, second... part of message. !!!But the common e-mail with HTML formatted text contains the first part as SUBTYPE: ALTERNATIVE in my example it contains 2 subparts: TEXT/PLAIN and TEXT/HTML Can I use two separated imap_fetchbody commands to take two subparts (PLAINTEXT and HTML)? If it is possible - how look the last parametters in imap_fetchbody commands? Can somebody help me? Thanks! Ketan