Start Validating dropdownlist in javascript

Validating dropdownlist in javascript

We use return false; because when this function is called when the form is submitted and if this textbox is found empty the page shouldn’t be submitted so returning the boolean value false with prevent the form from being submitted.

We need to check if it is equal to null or “” because different browsers act differently so its better to check for both the conditions.

The following function checks whether the texbox with id name1 is empty, if empty it displays a message and highlights that textbox with red color.

This post collects all my notes and references on j Query Form validation library.

This includes a large bunch of sample code and a complete reference guide to all the built-in validation rules in the library.

But what if I only want to enable the validation of certain field based on certain conditions?

Or if I want to validate based on an event that is not the But what if I want to enable the validator from javascript?

I didn't find anything online about this so I debugged the ASP.

NET js validation library to look for the method that enables the validation, and for the one that forces the validation check.

In Javascript we create a function which checks if some value is entered in the textbox or selected in the case of combobox, radiobutton, checkbox.

If a textbox is empty or an option is not selected we can use javascript to display an alert message, and highlight the empty field and also we should make sure the page stays the same and doesn’t get “submitted” Javascript validation is a client side validation and relies on the web browser so it should not be solely relied upon Textbox is the simplest element to validate if empty or not.

Now if Drop Down List is getting populated from Data Base by Sql Data Source then we need to set Append Data Bound Items property of dropdown to true and add one list item with text Select at 0th index in Page_Load event.