Input file css prob

I want to know how to give css properties to input file tag:
<input type="file">
This comes with a textbox and a browse button.
Can anyone help on this? I want to upload something on my contact form.

 

There are plenty of tutorials for styling the input tag, like these:
http://www.quirksmode.org/dom/inputfile.html
http://articles.sitepoint.com/article/style-web-forms-css

What do you want to change?

 

Thanks, i think 1st link is helpful. I wanted to style this: input type="file".