Copyright  Goodheart-Willcox  Co.,  Inc.  548  Unit  3  Living  Online  Adding  JavaScript  to  a  Web  Page  It  is  relatively  easy  to  incorporate  some  basic  JavaScript  code  into  a  web  page.  For  example,  an  alert  can  be  added  to  the  AboutMe.html  web  page  created  earlier.  1.  Applying  what  you  have  learned,  open  the  AboutMe.html  fi  le  for  editing.  2.  Below  the  h1  end  tag,  enter  the  following  code.  script  alert  (“My  first  Web  page!  Woo  Hoo!”)  /script  3.  Save  the  fi  le,  and  load  it  into  a  web  browser  to  see  the  alert.  4.  Applying  what  you  have  learned,  edit  the  script  so  the  alert  displays  A  short  biography  of  your  name.  5.  Verify  the  change  in  the  browser.  Hands-On  Example  13.2.4  PHP  and  Other  Preprocessors  A  preprocessor  language  is  required  to  provide  database  support  to  a  web  page.  PHP  hypertext  preprocessor  enhances  interactions  and  supplies  database  support  using  structured  query  language  (SQL).  Early  applications  of  PHP  were  address  books  and  forum  development.  This  functionality  is  not  handled  by  the  hypertext  protocol.  An  additional  program  must  be  running  on  the  server  to  handle  these  fi  les.  The  fi  lename  extension  is  .php.  Because  the  rendering  of  the  PHP  code  to  HTML  is  performed  at  the  host,  not  by  the  user’s  computer,  it  is  called  a  server-side  technology.  Preprocessing  functions  as  follows,  as  shown  in  Figure  13-25.  Notice  an  additional  step  is  added  to  the  process  shown  in  Figure  13-4  at  the  beginning  of  this  chapter.  1.  The  user  either  enters  a  location  in  the  navigation  bar  of  a  web  browser  or  clicks  a  link  on  a  web  page,  which  issues  the  URL  for  a  document  to  the  browser.  FYI  FYI  The  original  name  for  PHP  was  personal  home  page.  World  Wide  Web  1.  User  enters  URL  7.  Browser  displays  content  6.  Document  is  delivered  to  computer  via  HTTP  4.  Document  is  delivered  to  host  via  TCP/IP  5.  If  document  is  not  HTML,  it  is  sent  to  preprocessor,  which  generates  the  HTML  page  2.  Browser  transmits  to  host  server  3.  HTTP  locates  document  Goodheart-Willcox  Publisher  Macrovector/Shutterstock.com  Figure  13-25.  Preprocessing  involves  one  more  step  than  normal  web  processing.