I need to delete all unused groups that are in my site.I can get list of all groups but not able to list groups that are unused past long time.Can anyone help me in this??

Got to know that Using SPWeb.SiteGroups/SPWeb.Groups, SPRoleAssignment,SPRoleDefinitionBindings properties and classes I can achieve this.Only step where I failed is how to check the exact permissions assigned.One possibility is that there might be users, who created groups but din't knew the importance of assigning roles or permisssions to it, and still used that group with any contents.

Right now I found that Webservice UserGroup.asmx might be helpful.

It takes the GroupName as input and gives me the role collection from group.

But not getting how to consume this webservice.

Help would be appreciated a lot