Lead To Opportunity Attachement using javascript in crm4.0

function OnCrmPageLoad()
{
         var originLead = crmForm.originatingleadid.DataValue;
         if( originLead == null )
            document.all.tab3Tab.style.display = "none";
         else
{
              var iframeLeadNotes = document.all.IFRAME_leadNotes;
                   iframeLeadNotes.src = "/" + ORG_UNIQUE_NAME + "/_controls/notes/notesdata.aspx?id=" + originLead[0].id + "&ParentEntity=4&EnableInlineEdit=true&EnableInsert=false";
         }
}