Adobe GoLive CS2 Programmer's Manual page 122

SDK Programmer's Guide
Retrieve the gridLayout object from the markup object that represents the HTML source element it
edits:
markupObj
This example gets an <img> element that has been placed on a grid, then uses its gridLayout methods
to set its size, position, and alignment:
myImg = document.documentElement.getSubElement("img");
myImg.layout.gridLayout.setPosition(0,0);
myImg.layout.gridLayout.setSize(100,100);
myImg.layout.gridLayout.halign = "center";
Adobe GoLive CS2 SDK
.layout.gridLayout
Editing with Layout 122