KCFinder and CKEditor not working when hosted in different server

I am integrating KCFinder(v2.51) with CKEditor(v 4). If both hosted in same server, its working fine. But I want to keep these two in different server to keep all uploaded files into another server. In CKEditor config.js file, I given like this : config.filebrowserBrowseUrl =http://serverIPhere.com/contentserver/KCFinder/browse.php?type=files and in KCFinder config.php, 'uploadURL' => "http://serverIPhere.com/contentserver/", 'uploadDir' => "E:/CONTENTSERVER", When I click on browser server, application open KCFinder window and I can upload images. But when i double click on any images, it's not adding into previw/ckeditor. But If both KCFinder and CKeditor are in same server, it works great. Can any one please help me to solve the problem.