Hi Guys, I want to get all the contact which belongs to customers only, which filter i need to add.

var contactSearchObj = search.create({
   type: "contact",
   filters:
   [
      ["internalid","anyof","4940"]
   ],
   columns:
   [
      search.createColumn({
         name: "entityid",
         sort: search.Sort.ASC,
         label: "Name"
      }),
      search.createColumn({name: "email", label: "Email"}),
      search.createColumn({name: "phone", label: "Phone"}),
      search.createColumn({name: "altphone", label: "Office Phone"}),
      search.createColumn({name: "fax", label: "Fax"}),
      search.createColumn({name: "company", label: "Company"}),
      search.createColumn({name: "altemail", label: "Alt. Email"}),
      search.createColumn({
         name: "accountnumber",
         join: "customer",
         label: "Account"
      }),
      search.createColumn({
         name: "internalid",
         join: "customer",
         label: "Internal ID"
      })
   ]
});
var searchResultCount = contactSearchObj.runPaged().count;
log.debug("contactSearchObj result count",searchResultCount);
contactSearchObj.run().each(function(result){
   // .run().each has a limit of 4,000 results
   return true;
});