Implementation to send variables through the url (with javascript) like PHP $_GET.

[Twey]

Because the URL may contain characters such as %2e, which should be unescape()ed back into their original unencoded forms (. in this case).

[mwinter]

Can you please explain why ... you used this line:

return match ? unescape(match[1]) : null;

while

return match[1];

works fine?

For what definition of "works"?

Yes, if the regular expression is always matched (if the sought parameter is always present), then the exec method will always return an object reference. However, if a parameter is absent the return value will be null, and attempting to access a property of a null value will cause a run-time error.

Mike