function autofill()
{
 var formtype =Xrm.Page.ui.getFormType();
 
 if (formtype==1){
 
  var objlookup = Xrm.Page.getAttribute("new_contact").getValue();
  if (objlookup!=null)
  {   
   var fetchXml= "<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false'>"+
        "<entity name='contact'>"+
       "<attribute name='fullname' />"+
       "<attribute name='telephone1' />"+
       "<attribute name='contactid' />"+
       "<attribute name='emailaddress1' />"+
       "<attribute name='mobilephone' />"+
       "<order attribute='fullname' descending='false' />"+
       "<filter type='and'>"+
         "<condition attribute='statecode' operator='eq' value='0' />"+
       "</filter>"+
        "</entity>"+
      "</fetch>";
   var _contact = XrmServiceToolkit.Soap.Fetch(fetchXml);
   if (_contact.length > 0){
    var fullname="";
    var mobilephone="";
    var email="";
    if (_contact[0].attributes.fullname != undefined)
     fullname = _contact[0].attributes.fullname.value;
    if (_contact[0].attributes.mobilephone != undefined) 
     mobilephone = _contact[0].attributes.mobilephone.value;        
   }    
  }
 }
}

if (_contact[0].attributes.fullname != undefined)
{
 //you code here
}