Want to the trim post description characters

Topics: Themes
Nov 20, 2014 at 3:45 AM
Need to display blog post description characters only upto 400 characters, if the description exceeds, need to provide more. If user he click the more, he/she must be able to view yhe full description.

Eg:

dbkjdhlsjdiSMNDKLXHNKUDHKWJ,SNDJK... more