function input Alphabet(inputtext, alert Msg) // Function that checks whether input text includes alphabetic and numeric characters.function text Alphanumeric(inputtext, alert Msg) // Function that checks whether the input characters are restricted according to defined by user.If the REQUEST_METHOD is POST, then the form has been submitted - and it should be validated.
Here I am giving you the form validation codes in Java Script. These are simple meta characters which do pattern matching. If the entered characters in the field is not in lower case or upper case. When it’s about checking contact field or zip code field, one need to check whether only the number have been entered or not.Be aware of that any Java Script code can be added inside the - this would not be executed, because it would be saved as HTML escaped code, like this: <script>location.href(' The code is now safe to be displayed on a page or inside an e-mail.We will also do two more things when the user submits the form: The next step is to create a function that will do all the checking for us (which is much more convenient than writing the same code over and over again). Now, we can check each $_POST variable with the test_input() function, and the script looks like this: Notice that at the start of the script, we check whether the form has been submitted using $_SERVER["REQUEST_METHOD"].Regular expression helps you in pattern matching in string. : Matches any single charcter except a new line : Matches the preceding character or repeated character. The basic expression for matching entered value as number in the field is: /^[0-9] $/. [A-Z] : It matches characters from uppercase ‘A’ to lowercase ‘Z’. The codes for checking form empty fields are given below: There is an expression that checks whether the string contains only alphabets or not.