How to retrieve ID field of a Custom object using Javascript API

Content

Hi All,

I have a Custom Object workspace and would like to run a script(using Javascript API) on it that accesses the ID value of the Object along with other custom fileds in it.

var co= window.external.GetCustomObject("co", "test");
         var f1= co.GetCustomFieldByName("field1");
         var f2 = co.GetCustomFieldByName("field2");
         var f3 = co.GetCustomFieldByName("field3");
         var id =  co.GetCustomFieldByName("ID");

 

fields f1,f2,f3 are retrived succesfully but id returns undefined.

 

Could anyone help.