About ajax+jsp implementing asynchronous validation of the existence of an instance of the user name (. txt text)

Source: Internet
Author: User

Effect Demo:

  

Description
1.onreadystatechange Event trigger for request state change (this method is called when readystate changes)
2.readyState has v Status:
ReadyState = 0 Not initialized
ReadyState = 1 means the Open method was successfully called
ReadyState = 2 The server has answered the client request
ReadyState = 3 in the interaction. The HTTP header information has been received and the response data has not been received.
ReadyState = 4 Data reception complete.
3.onblur method: How the text box responds when it loses focus,
<span id= "mydiv" > </span><br> tips for placing a check
4. Verification steps:
Create a XMLHttpRequest object----> Create an HTTP request-----> Send an HTTP request------> Return a request-----checksum.
This example is the connection TXT text file implementation verification

Connection database Check mode reference: http://blog.csdn.net/javaalpha/article/details/6559176

About ajax+jsp implementing asynchronous validation of the existence of an instance of the user name (. txt text)

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.