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While testing an ASP validation control in Internet Explorer I found that the validation wasn’t triggered if I selected an item from the autocomplete list for a text box, this was the same in Safari for Windows, but worked fine in Mozilla Firefox. What?!
Turns out that when selecting an item from the autocomplete list the onchange event handler doesn’t fire, therefore the validation scripts don’t fire. The onblur event does fire however, meaning we can do a check to see if the data has changed and if so, manually fire the onchange event handler.
Alternatively, you can disable the autocomplete feature by adding the attrribute autocomplete="off" for either a specific input or for the entire form.
Download the entire code sample including the addEvent() function.