Creating a variable name using a variable

Hi all, I'm new to the list. Hopefully this is not too frequently asked... Now I realise I should probably be using an array. But it would be nice to occasionally create a variable name from a variable. For example: I have 3 variables $url1, $url2 and $url3. I have another variable $i (which takes one of the values 1, 2 or 3). If $i=2 is there any way I can refer to $url2 using by combining "$url" and $i? Many thanks, Adam PS: To the developers of PHP many thanks. PHP is awesomely fun and powerful.