i m sorry i a newbie in this website. i have a confuse question here.
why when i added reputation to someone that i think good post, its does not work normally. in this case i already chosen approve, but the mark is gray. if i choose disapprove i got the same color mark too.how i can add a green reputation to someone?? what different if i fill and didn't fill the comment but i still choose approve selection?

The mark is only grey because it means that you don't have enough rep power yourself to influence his reputation. Your rep power is currently 0. Your rep power is based on how long you've been a DaniWeb member, how many posts you have, and what your own reputation is.

This prevents the situation of abusing reputation by registering lots of different new users just to give yourself positive reputation. Only after you've reached an activity threshhold does the rep you give start really affecting the person's reputation.

Until then, your rep comments can still be seen within the posts and in member profiles.

hmmm...so like that. thx for explaination cscgal.
all for the best.