Getting error while uploading multiple files with REST API

Question

Hi All,
 In one of my tasks,i was struck with one issue,that is "While uploading multiple files into document library with REST API". Iam trying to upload multiple files in library with REST calls for an APP development,my issue is if i wants to upload 4 to 5 documents at once its storing only 3 documents and further giving "Conflict" error".below is the attached screenshot of exact error. Error within screenshot are : status Code : 409 statusText :conflict I have searched many blogs but i didnt find any solution,can anyone please help me on this issue

http://www.flickr.com/photos/112048958@N06/11461491596/[^]

Thanks in advance,
 Naresh