Blog entries meta description & Google indexing problem

[Micronichos]

Hello, I have a problem with the blog entries meta description, they have only the title of the post and title of the blog and don't have for example the first 50 characters from the blog entry.

The result is duplicate content and Google not indexing all blog entries from my users, it's really a problem for me since my users posts ads and I need most visibilty from crawlers.

How can I add the first 50 chars from the blog entry to meta description of that blog entry?

Thank you in advance.

--------------- Added [DATE]1277037785[/DATE] at [TIME]1277037785[/TIME] ---------------

In headinclude I add blog.message variable but nothing is added to description, do you know what is the problem?

<meta name="description" content="{vb:raw vboptions.description} {vb:raw blog.message}" />

gives the same result as:

<meta name="description" content="{vb:raw vboptions.description} " />