Explanation/Reference:
* style.position = "relative";
The element is positioned relative to its normal position, so "left:20" adds 20 pixels to the element's LEFT position.
* For relatively positioned elements, the top property sets the top edge of an element to a unit above/below its normal position.
Example: Example
Set the top edge of the image to 5px below the top edge of its normal position:
img {
position: relative;
top: 5px;
}
Reference: CSS position Property; CSS top Property
http://www.w3schools.com/cssref/pr_class_position.asp
http://www.w3schools.com/cssref/pr_pos_top.asp