Setting permissions to Add Comments of Jom Comment in Joomla1.5

Question

Hi, I am having Jom Comment installed in my Joomla1.5. i have created a section namely userblog - Section blog layout type. By default , under every blog post under tat section i am having a Add COmment(0) link which allows to add comment to the blog post.

How to set permisssions for allowing only some group members to add the comments??

How to get the View comment link under each blog post.. Instead of getting Add Comment(2).???

Please help me .... Thanks in Advance.