[](http://www.uploadify.com) # checkScript Input Type:**string** Input Format:**null** Default:**null** Required:**optional** The **checkScript** option allows you to check the upload folder for any files that exist with the same name as any files that are in the queue for upload. The back-end script should return a JSON encoded array of the matching file names in order for this option to work. ### Demo Javascript Code 1. $('#file_upload').uploadify({ 1. ? 'uploader' ? ?: '/uploadify/uploadify.swf', 1. ? 'script' ? ? ?: '/uploadify/uploadify.php', 1. ? 'cancelImg' ? : '/uploadify/cancel.png', 1. ? 'folder' ? ? ?: '/uploads' 1. }); HTML Code 1. <inputtype="file"id="file_upload"name="file_upload"/> 1. <ahref="javascript:$('#file_upload').uploadifyUpload();">Upload Files</a> [Upload Files](#) [](#) Help keep Uploadify free and support the development of other excellent apps!  [home](#) ?|? [about](#) ?|? [download](#) ?|? [demos](#) ?|? [documentation](#) ?|? [faqs](#) ?|? [forums](#) ?2011 by [Reactive Apps](http://www.reactiveapps.com)