Q:

How to parse this JSON correctly?  Says its property is undefined

I'm trying to parse this json string and it's not working.  It's giving me a syntax error in chromes javascript console and firebug.  Any help would be greatly appreciate!  Thanks much! 
"{ "SUCCESS" : false, "DATA" : '', "ERRORS" : [ "duplicate item" ]}"

Uncaught SyntaxError: Unexpected token ILLEGAL

here's my code:
var json = objResponse;
//var obj = JSON.parse(json); //this doesn't work either
var obj = jQuery.parseJSON(json);

alert(obj. SUCCESS);

A:

Your problem is the single quotes (') for DATA. 
This helped me out:
http://json.parser.online.fr/

A:

Don't mismatch your quotes or your quote types, for example: 
'{ "SUCCESS" : false, "DATA" : "", "ERRORS" : [ "duplicate item" ]}'

Will parse just find.  An additional note, single quotes are not valid for a JSON string. 

A value can be a string in double quotes, or a number, or true or
  false or null, or an object or an array.  These structures can be
  nested.