How to tweak newly added scroll item's position?

[leegod]

I want to change newly added scrollview item's position to very left or right edge from the item list.

But like this video, http://youtu.be/uNoHElA63gU

newly added item only generating at position of 2nd from most left item.

How can I change this position manually to most left(or right) edge of scroll list?

Thanks.