using a custom post page title..please help..!

hello everybody

here is my wordpress blog https://www.Decentsms.com

i want to edit the post title

my current post title is like this

and code is:

<?php bloginfo(‘name’); ?> <?php if ( is_single() ) { ?> » Blog Archive <?php } ?> <?php wp_title(); ?>

i want my Title to appear like this

Category name >> Post Name

is any body there who can do this