// Get the grid
var relationshipsId = window.relationshipsControl.currTabID;
var relationshipsFrame = window.frames[relationshipsId];
var gridApp = relationshipsFrame.contentWindow.gridApplet;
// Get the value of the selected cell
var selCell = gridApp.getSelectedCell();
var cellValue = selCell.getValue();
Please note that there is currently a bug filed with the getSelectedCell()
method where it returns incorrect results if the relationship grid displays a mix of properties on the related ItemType as well as on the relationship ItemType.
Chris