Update README.md

README.md

@@ -1,5 +1,8 @@
 jQuery File Download is a cross server platform compatible jQuery plugin that allows for an Ajax-like file download experience that isn't normally possible using the web.
 
+###Demo (of this exact source):
+http://jqueryfiledownload.apphb.com/
+
 ###Source here:
 https://github.com/johnculviner/jquery.fileDownload/blob/master/src/Scripts/jquery.fileDownload.js
 
@@ -8,6 +11,13 @@ This might be a better solution to your problem https://github.com/eligrey/FileS
 
 ### Requirements
 * jQuery 1.6+
+
+### Common questions and answers
+* Q: I need to send in custom headers. How do I do that?
+  *  Unfortunately since this plugin uses an iframe and not AJAX you cannot send in custom headers. If you really need to do this and are willing to accept a more narrow range of browser support this might be a better solution to your problem https://github.com/eligrey/FileSaver.js/
+* Q: It doesn't work!?
+  * Try out the demo and make sure you are doing exactly what it is doing: http://jqueryfiledownload.apphb.com/ If the demo doesn't work in your browser you have defintely found a bug and us know!
+  * Due to iframe security restrictions you must serve up the file from the same domain you see in the address bar
 
 ### Supported and tested browsers
 * Internet Explorer 6+ - Works fine for standard use cases except in < IE9 JavaScript access to the *failed* response HTML doesn't (and can't) work reliably due to browser iframe constraints.
@@ -16,8 +26,6 @@ This might be a better solution to your problem https://github.com/eligrey/FileS
 * iOS 5.0+ - reasonably sure it will work on earlier versions
 * Android 4.0+ - non-GET requests do not work due to a long-standing [bug](http://code.google.com/p/android/issues/detail?id=1780) in the Android browser. This is handled 'gracefully' with a message to the user.
 
-###Demo (of this exact source):
-http://jqueryfiledownload.apphb.com/
 
 #Note - You must also write a cookie in conjunction with using this plugin as mentioned in the orignal post:
 http://johnculviner.com/post/2012/03/22/Ajax-like-feature-rich-file-downloads-with-jQuery-File-Download.aspx