js closure usage

gistfile1.js

      for (var i = 0; i < this.allCommentSize; i++) {
        (function(i) {
          //when this element is displayed
          if (uiActivity.commentBlockEls[i]) {
            Util.addEventListener(uiActivity.commentBlockEls[i], ['mouseover', 'focus'], function(evt) {
              uiActivity.deleteCommentButtonEls[i].className = 'CloseContentBoxHilight';
            }, false);

            Util.addEventListener(uiActivity.commentBlockEls[i], ['mouseout', 'blur'], function(evt) {
              uiActivity.deleteCommentButtonEls[i].className = 'CloseContentBoxNormal';
            }, false);
          }
        })(i);
      }