Populating Sub Grid with Related Records

I created a form property script to populate a sub grid on the lead form with all other leads containing the same company name. My script is terminating but the sub grid is still empty. I am thinking it has something to do with my fetchXml.

In other words, the sub grid should show a relationship from one lead to N leads with the same company name.

function setLeadStakeholders()
{
   var relatedLeads = window.parent.document.getElementById("lead_relatedbycompany");
   var lookupfield = new Array;
   lookupfield = Xrm.Page.getAttribute("companyname").getValue();
   if(lookupfield == null){ return; }
      var fetchXml = "<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false'>"+
          "<entity name='lead'>"+
          "<attribute name='fullname' />"+
          "<attribute name='companyname' />"+
          "<order attribute='fullname' descending='false' />"+
          "<filter type='and'>"+
          "<condition attribute='companyname' operator='eq' value='" + lookupfield + "' />" +
          "</filter>"+
          "</entity>"+
          "</fetch>";
     if(relatedLeads.control != null){
            relatedLeads.control.setParameter('fetchXml', fetchXml);
            relatedLeads.control.refresh();
     }else{
     setTimeout(setLeadStakeholders, 2000);
     }
}