Get a lookup value
var lookup = new Array();
lookup = Xrm.Page.getAttribute("attributename").getValue();
if (lookup != null) {
var name = lookup[0].name;
var id = lookup[0].id;
var entityType = lookup[0].entityType;
}
Set a lookup value
var lookup = new Array();
lookup[0] = new Object();
lookup[0].id = recorid;
lookup[0].name = recordname;
lookup[0].entityType = entityname;
Xrm.Page.getAttribute("attributename").setValue(lookup
