how to submit many data files once using ajax in Extjs

how to submit many data files once using ajax in Extjs

Now, I have a task. import many excel files once in batch mode. firstly,
the number of files is about some hundreds. I can't submit in one ajax
request. They are too large.
So, I try to submit many ajax request in turn in one function(in
CodeIgniter).
then, I hope to track them.
waitmsg is good, but every ajax request has itself waitmsg. I hope just one.
like a normal progress bar, first file ,second file ... the x hundredth file.
Can you help me?
Thanks a lot.