get lookup value and id using javascript in mscrm 2011

function getlookup()
{
var lookupObject = Xrm.Page.getAttribute("primarycontactid");

if (lookupObject != null)
{

var lookUpObjectValue = lookupObject.getValue();

if ((lookUpObjectValue != null))
{

var lookuptextvalue = lookUpObjectValue[0].name;
alert(lookuptextvalue);

var lookupid = lookUpObjectValue[0].id;
alert(lookupid);

}
}
}