Jquery validate file extension even after rename file

Question

I am trying to make a web application where I want to validate the file extension even after name change on File Upload Control, I did some research and found Dataview solution but it is still with some lack since I found extension doc, xls, msi with the same Header Signature. If you can help me out with this it would be great. I can't use server side code since it has to be validate before uploading file. My main Goal is to Prevent the User from Uploading the Wrong File Type on any Condition.