tailieunhanh - PHP Developer's Dictionary- P9

PHP Developer's Dictionary- P9:PHP is an open source, server-side, HTML-embedded scripting language used to create dynamically generated Web pages. With an easy-to-use syntax and a large, extensible library of modules, PHP brings together the best of Perl, C++, and other languages. | PHP Developer s Dictionary echo Password . Password. br body html Session variables are very useful and can be the means of validating permissions to Web pages. This type of validation can be as simple as an if-then conditional that checks for a valid login name and password. This check can display an error message if the check does not pass or display the content if the permissions are appropriate. Working with Email Email is a very useful tool and one that is easy to use as long as you understand the workings of the email system. Email can automatically notify users of important events and provide details of user accounts or other information. Email can also be used to send dynamic bulk information to a group of users. Email like other areas of PHP is flexible and is limited only by your imagination. Email Overview This is a general overview of how email works on the Internet. Please realize that there are many varieties of email clients and email servers this is just an overview and describes some of the mechanisms on which most every Internet email systems rely. All standard email messages contain certain information such as the sender s name and email address the recipient s name and email address a subject for the message and some kind of message in the body of the email. Email messages are composed of two basic parts the headers and the body. Headers define where the email is going and any special routing information. Generally the user does not see this information. Email clients usually format the content in a user-friendly manner and mask this information from the user. After an email is composed the email client or Mail User Agent MUA sends the information to the SMTP host or Mail Transfer Agent MTA . SMTP stands for Simple Mail Transfer Protocol and is the foundation for virtually all Internet email messages. The SMTP host takes the message and adds additional information to aid in the routing of the email. The MTA is responsible for delivery of the .