All you need to do is include a This tells the browser that the form should not be allowed to submit without the checkbox checked.Some, but not all, browsers will recognise and enforce this: The advantage of the HTML5 form validation is that it happens before our Java Script is called, displays instructions and points the user to the relevant element.While HTML5 form validation is typically about missing or invalid text inputs, there are other form element types that also require attention. Suppose you have a form on your website that at the bottom asks people to "accept the Terms and Conditions" or something similar.Basically you don't want the form to be submitted unless this is checked.If you are building a site that is form intensive (let’s say an online instruction course website) and the user would like to clear text boxes that he has inputed because he is not happy with his answer.Instead of the user going through and deleting all of the answers himself, we will create a button and tie an event to it that will clear all Text Box fields for him.[Code explanation] On the button click procedure write the code to create an object of Text Box class, and set the properties like name, Size and location, and then we add this control to Group Box control with the help of Controls.Add() function.[Create Dynamic Label][Add event at run time]From the above we create controls at run time and now we move to next step- create event handler at run time and attach that event to the control.
Expand the toolbox panel and grab and place a Button item inside the open and closing div tags. On a larger project, a more maintainable approach is required that would look for all Text Boxes within a given field and remove the character strings.Please refer to the errata for this document, which may include some normative corrections.The previous errata for this document, are also available. This document is also available in these non-normative formats: XML and XHTML with color-coded revision indicators.Using vanilla Java Script we can prevent form submission as follows: All this does is confirm before submitting the form that the checkbox is checked.If not, an alert is displayed and focus is moved to the checkbox.