Editor’s note: HTML form normally submitted with a button, however in some cases when the user wants to have an action (submit some data to another page) by clicking a radio button, a little javascript would do the job, and here is an example:

We use HTML form a lot for the user to input data and process those data from a PHP file, but with the standard code of a HTML form:

Editor’s note: There is a function in PHP to check the IP address of a host. It is called “gethostbyname()“. We could use it to check the IP address of a website. Steps are very simple: Put the website address into the function, for example: gethostbyname(www.phpsuperblog.com); and print the result out and then the IP address of the website would appear.

Editor’s note: To create a HTML form with just a few text fields and a few HTML form elements is easy, but in a stock control system or price input system for example, there might be a need for many text fields and different HTML form elements repeatedly appear in the HTML form. To type in the codes of all of them will take too much time. Therefore a PHP for loop and a table is good for this task.

Editor’s note: In some cases which the user might need to empty a table in the MySQL database. Instead of deleting every record in the MySQL database, you could run a query “truncate table ‘tablename’” to do the job.

Editor’s note: In a login system, there are user names and passwords stored in the MySQL database. The passwords are normally stored as strings inside the database. To have a more security way to store the passwords in the database, it is better to store an encrypted version of the password, therefore only the password creator knows what the password is.

MD5 is the encryption technology I like to use because it is very easy to implement and it encrypts a string into a 32-character strings, for reference what MD5 really is, please check Wikipedia-MD5.