Combobox validating

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.

An HTML combobox shows a dropdown list of items from which one item is selected.

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.

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The simple combobox validating feature has been successfully added to combobox.

After you run the application, if you click the submit button before you select a valid value for each field, the validation function will be triggered and display the error image to remind you to enter a valid value.

Use this event to provide custom validation for any input control, such as a Text Box. In other words, the validating control will retain the focus until the user provides the correct format, even if the user clicks another control such as a button or textbox.

I.e., the caret will remain in the textbox until the user enters the correct format.

By default the caption for that list is the first item.

For example if you’re asking a user to select a country the first option is “Select a country” and the name of the countries follow so we need to check if the first option is selected and then display a message to select an option.

Important: Never attempt to set the Focus of a control in this event because it can cause the script to hang.

This event occurs when the control is finished validating.

This validator does not check whether the credit card is an actual active credit card account.


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