The method used by the client-side must be the same as defined by the server-side program (get).
The field names used by the client-side must be the same as specified by the server-side program.
URLs can only be sent over the Internet using the ASCII character-set.
Since URLs often contain characters outside the ASCII set, the URL has to be converted into a valid ASCII format.
URL encoding replaces unsafe ASCII characters with a "%" followed by two hexadecimal digits.
URLs cannot contain spaces. URL encoding normally replaces a space with a plus (+) sign or with %20.
e.g. For username=Peter 彼得 and password=123456, the URL after submitting the form becomes: