url_decode
This function decodes a URL compatible string back to its standard form.
string url_decode(string url)
Parameters:
url
The encoded URL string to decode.
Return value:
The decoded string on success, or the passed string on failure.
Remarks:
The url_decode function changes special character combinations in URL's that represent spaces and other symbols back to their ASCII equivalents.
Example:

    // Decode a URL.

    void main()
    {
    alert("Decoded URL",url_decode("http%3a%2f%2fwww.mysite.com%2ffiles%2fmy+program+%28v1.0%29.exe")); // Reads http://www.mysite.com/files/my program (v1.0).exe
    }