The illustration below shows this relationship: Note that the 'I' in selected Index needs to be capitalised - Java Script functions and variables are always case-sensitive. Read more about the humble checkbox in our HTML5 Checkbox Validation article.
Radio buttons are implemented as if they were an array of checkboxes.
The purpose of a form validation script is to return a boolean value ('s to reference form fields, but that can lead to namespace conflicts and why make things more complicated than necessary.
When the form is submitted - either by hitting Enter or clicking on the Submit button - the (the 'value' of the field called 'input' belonging to the form). In a real-life situation you will most likely have more fields to check, and more complicated conditions, but the principle remains the same.
When form input is important, it should always be verified using a secure server-side script.
In other words, whenever a person first clicks an element, and then clicks anywhere outside of it. Onblur is used when you want to check each element (ie: text, textarea boxes ) individually, and ask the user to correct the input before moving on to the next box.
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.
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] $/.
But if the user unchecks the box, the user DOESNT have to enter info in textarea.
To check, whether the user entered correct form of data, it’s must to apply form validation in any of the form. The expression is: /^[a-z A-Z] $/ The above expression checks whether the input characters in the string is alphabet or not.
Tried setting it up on onsubmit on both form and button and no go.