MS CRM 2011 & 4.0 How to set up a lookup using Javascript

Javascript for MS CRM 2011

var value = new Array();
value[0] = new Object();
value[0].id = id;
value[0].name = textvalue;
value[0].entityType = typevalue;
Xrm.Page.getAttribute("fieldname").setValue(value);


Javascript for MS CRM 4

var value = new Array();
value[0] = new Object();
value[0].id = id;
value[0].name = textvalue;
value[0].typename = typevalue;
crmForm.all.fieldname.DataValue = value;