Need some quick help with a function

I am the first to admit that I know bupkis about javascript, except that
sometimes I need it to do something client side that I can't do server
side.

Anyway, here's my problem:

<input type="text" name="ticket" id="ticket">
<input type="text" name="amount" id="amount">

My ASP script defaults ticket to be 30.00 and amount to be 600.00. What
I need is if the visitor puts 50.00 into the ticket field, the amount
field will update to 1000.00 instead of 600.00, in other words, ticket is
5% of amount.

Normally, I would Google and find tutorials or code snippets, but I've
got a deadline. I would really appreciate some help with this.

Thanks in advance.

-- 
Adrienne Boswell
http://www.cavalcade-of-coding.info
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