How To Change Search String /?s= with some other name

Hello Alex,

First of all, thanks for making such a great theme. I got less words to express this because of the work you did in developing the theme is outstanding.

The reason for me to buzz you is because I got a question to ask, I am using the theme in my website http://hundredcoupons.com/ and I would like to ask you that how can I change the http://hundredcoupons.com/?s=HTC (for example) to http://hundredmovies.com/?(any-other-word-here)=HTC i.e. instead of “s” how can I put some other word here.

Thanks and looking forward for the response from you.

Best,
Karan