Sorry for the delay, I haven't been keeping an idea on this topic.
Give yourself moderator access on the forum Ideas is posting in, and you will see a number of moderation options on the idea itself:
See the bottom row.
Thanks - I've Moderator access. I think there is some more to it. Please have a look at this link: http://www.ibm-mainframes.com/ideas/index.php
. Look for "This is test idea" and "Test 2" under "TOP IDEAS" and please suggest what can I do for them, as when I click on then it shows "The requested topic does not exist."