(đối với cột số) là những giá trị thực (không NULL). Các lĩnh vực trọng điểm chính không thể cho phép NULLs. Đôi khi thay vì (hoặc bổ sung cho) không cho phép NULLs cho một lĩnh vực nhất định, bạn có thể | AJAX Form Validation class php echo _SESSION errors txtBthYear Please enter a Valid date. span br Email label for txtEmail E-mail label input id txtEmail name txtEmail type text onblur validate value php echo _SESSION values txtEmail span id txtEmailFailed class php echo _SESSION errors txtEmail Invalid e-mail address. span br -- Phone number -- label for txtPhone Phone number label input id txtPhone name txtPhone type text onblur validate value php echo _SESSION values txtPhone span id txtPhoneFailed class php echo _SESSION errors txtPhone Please insert a valid US phone number xxx-xxx-xxxx . span br -- Read terms checkbox -- input type checkbox id chkReadTerms name chkReadTerms class left onblur validate php if _SESSÌ3N values chkReadTerms on echo checked checked I ve read the Terms of Use span id chkReadTermsFailed class php echo _SESSION errors chkReadTerms Please make sure you read the Terms of Use. span -- End of form -- hr span class txtSmall Note All fields are required. span br br input type submit name submitbutton value Register class left button form fieldset body html 7. Create a new file named and add the following code to it php clear any data saved in the session session_start session_destroy DOCTYPE html PUBLIC - W3C DTD XHTML EN http TR xhtml11 DTD html xmlns http 1999 xhtml head title AJAX Form Validation title meta http-equiv Content-Type content text html charset utf-8 link href rel stylesheet type text css head 130 Chapter 4 body Registration Successfull br a href title Go back lt lt Go back a body html 8. Create a file named . This file performs the client-side functionality including the AJAX requests holds an instance of XMLHttpRequest Var xmlHttp createXmlHttpRequestObject holds the remote server address Var serverAddress when set to true display detailed error messages Var showErrors true
