_.frameId = CKEDITOR.tools.getNextNumber() + '_fileInput';\r
\r
// Support for custom document.domain in IE.\r
- var isCustomDomain = CKEDITOR.env.ie && document.domain != window.location.hostname;\r
+ var isCustomDomain = CKEDITOR.env.isCustomDomain();\r
\r
var html = [\r
'<iframe' +\r