Get a URL argument variable with Javascript

How do I get a $_GET[] argument with开发者_运维技巧 JavaScript?

http://www.example.com/?what=this

I want to get the value of "what" ...

You can get the raw string like this:

window.location.search

E.g., http://google.com/?whatIs=up

gives you ?whatIs=up

And then parse through it to get the different values for the different parameters.