uri_escapeuri, [regexp]
Given a URI as the first parameter, returns the equivalent URI with certain characters 
replaced with % followed by two hexadecimal digits. The first parameter can be a 
text string, like "http://www.oreilly.com", or an object of type URI::URL. When 
invoked without a second parameter, uri_escape escapes characters specified 
by RFC 1738. Otherwise, you can pass in a regular expression (in the context 
of [ ]) of characters to escape as the second parameter. For example:
This code escapes all lowercase vowels in$escaped_uri = uri_escape($uri, 'aeiou')
$uri and returns the escaped version.