daveVk - 10:07 pm on Nov 28, 2012 (gmt 0)

[api.jquery.com...]

Directional properties (top, right, bottom, left) have no discernible effect on elements if their position style property is static, which it is by default.

You may need to set style="position: relative;"

Also example at above link uses left: '+=50' in animate() ?