Setting a lookup field value

function sample()
{
debugger;
var ExistingCase = Xrm.Page.data.entity.attributes.get("new_userteam");

if (ExistingCase.getValue() != null) {
   var ExistingCaseGUID = ExistingCase.getValue()[0].id;
    var ExistingCaseName = ExistingCase.getValue()[0].name;

var lookupValue=new Array();
lookupValue[0] = new Object();
lookupValue[0].id=ExistingCaseGUID;
lookupValue[0].name=ExistingCaseName;
lookupValue[0].entityType="incident";
Xrm.Page.getAttribute("new_lapcounty").setValue(lookupValue);
}

}