what happen Onclick In Fileupload Browser buttons

i have a small doubt i.e when i click on FileUpload Browser Button how will the browser opens files contai开发者_如何转开发ns window

what method called when we click FileUpload Browser Button

The basic html would be:

<input type="file" name="datafile" size="40">

Is that what you were asking for?

I think this question might help you out:

How to make own file upload using HTML and javascript

You can't change the default behavior of the browser or "write" something to that window.

Most you can do is change the appearance of the file input button, but after it's clicked the window letting the user choose a file can't be changed.