Simple Ajax asynchronous Processing

  1   <!  Doctype HTML public "-// W3C // dtd xhtml 1.0 transitional // en" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"  >  
  2      <  Html  Xmlns  = "Http://www.w3.org/1999/xhtml"  > 
  3      <  Head  >  
  4      <  Meta  HTTP-equiv  = "Content-Type"  Content  = "Text/html; charsets = UTF-8"     /> 
  5      <  Title  >  Untitled document  </  Title  >  
  6   <  Script  Type  = "Text/JavaScript"  > 
  7   VaR  XMLHTTP;
  8   Function  Createxmlhttprequest ()
  9   {
  10     If  (Window. activexobject) //  Judge the asynchronous object type of the browser;  
  11   {
  12   XMLHTTP  =  New  Activexobject (  "  Microsoft. XMLHTTP "  );  //  Instantiate an asynchronous object;  
  13   }
  14     Else     If (Window. XMLHttpRequest)
  15   {
  16   XMLHTTP  =  New  XMLHttpRequest ();
  17   }
  18   }
  19  Function  Startrequest ()
  20   {
  21   Createxmlhttprequest ();  //  Call an asynchronous object;  
  22   XMLHTTP. onreadystatechange  = Function  ()  //  Response server call method;  
  23   {
  24     If  (XMLHTTP. readystate  = 4  )  //  Determine whether the request is complete  
  25   {
  26     VaR  A  = XMLHTTP. responsetext;  //  Obtain the data returned by the server and assign it to variable.  
  27   Alert ()
  28   }
  29   }
  30   XMLHTTP. Open ( "  Get  "  ,  "  Admin. php  "  ,  True  );  //  Use the get method to access a server-side URL link script and asynchronously process the creation of a server request 
  31   XMLHTTP. Send (  Null  );  //  Send a request;  
  32   }
  33   </  Script  > 
  34   </  Head  >  
  35   
  36   <  Body  >  
  37   <  Input  Type  = "Button" Value  = "Submit"  Onclick  = "Startrequest ()"     />   
  38   </  Body  >  
  39   </  Html  >  
 40   
  41   Admin. php
  42   <?  PHP
  43   Echo "My name is youyou"
  44   ?> 

 

Summary:

1: Judge the browser and instantiate the XMLHTTPRequest object;

2:CodeSegment;

3: Create a request to access the server scripting language through the open method;

4: Send this request using the send method;