js quirks in popular browsers

[briefy]

IE

Event quirks of IE

• make sure the specific versions

• use Event.returnValueto preventDefault and get the status whether the default has been prevented or not

• use Event.cancelBubble = true to stop event stopPropagation

vanilla js

• ie9 does not support the strict mode
• <= ie9 do not suport XMLHttpRequest,but XDomainRequest,
  however, <=ie9 do not support FormData,so you cannot send files with it
  related: example ---- XDomainRequest object