Validate a Drop-Down List on a Form

The easiest way to make ensure that a user picks a value from a dropdown list is to add a value to the top of the list that isn’t really a valid choice, but a prompt instead. Something like “select one” should do. Make sure to set the value of this dummy item to a known value that won’t conflict with the real choices in your list. Zero (0) and negative 1 (-1) are usually a safe bet. Then before you submit the form, double check and make sure that the selectedIndex property of the select object isn’t set to the dummy value. If it is, prompt the user to make a selection, otherwise use the form’s submit() method to submit the form.

Share the Post:
Share on facebook
Share on twitter
Share on linkedin


The Latest

microsoft careers

Top Careers at Microsoft

Microsoft has gained its position as one of the top companies in the world, and Microsoft careers are flourishing. This multinational company is efficiently developing popular software and computers with other consumer electronics. It is a dream come true for so many people to acquire a high paid, high-prestige job

your company's audio

4 Areas of Your Company Where Your Audio Really Matters

Your company probably relies on audio more than you realize. Whether you’re creating a spoken text message to a colleague or giving a speech, you want your audio to shine. Otherwise, you could cause avoidable friction points and potentially hurt your brand reputation. For example, let’s say you create a

chrome os developer mode

How to Turn on Chrome OS Developer Mode

Google’s Chrome OS is a popular operating system that is widely used on Chromebooks and other devices. While it is designed to be simple and user-friendly, there are times when users may want to access additional features and functionality. One way to do this is by turning on Chrome OS