use separate function instead of closure to support php < 5.3

git-svn-id: https://plugins.svn.wordpress.org/productwidgets/trunk@1004271 b8457f37-d9ea-0310-8a92-e5e31aec5664
tagged version v1.1.1

git-svn-id: https://plugins.svn.wordpress.org/productwidgets/trunk@1004272 b8457f37-d9ea-0310-8a92-e5e31aec5664