Batch cat plugin is very useful plugin for webmaster that has many post in their wordpress blog.
Since WordPress 3.1 You will find that Batch Cat Plugin not working.
when we assign post to category it will raise error “Please select at least one post !’” Or ”Please select at least one Category !’”
I try to find the solution in google, but with no luck.
So i decide to make fix for it 
, - I m kind of smart lazy programmer 
Finally i found the problem is in jquery selector. Latest jQuery selector has changed
Ok. Here is the fix.
1. Open batch-cat.js
2. Go to function bcat_get_posts() and function bcat_get_cats()
3. Change current line
var posts = $('input:checkbox:checked[name="postid[]"]');
To
var posts = $('input:checkbox[name="postid[]"]:checked');
4. and also make change below line too
var posts = $('input:checkbox:checked[name="catid[]"]');
To
var cats = $('input:checkbox[name="catid[]"]:checked');
and Viola Its working Now
