Instant form validation

When you think about javascript validation and when to trigger it the first thing you think about is the onblur event. The trouble with the onblur even is not everyone is tabbing through form so it's possible not all fields are validated. The same goes for a key event.

So most of the programmers use the click event to submit the form. The problem in asp.net is that if you use the asp:net button tag the javascript of the asp.net control is handled after your own javascript code so the form is processed even if you added return false for the event.

I don't know how to influence the control behavior yet so what i did is attach the validation to the button mouseover event. This way you see the errors before you even click the button.

I don't know why i haven't thought of that before because it's so easy and noticeable.

You can find a demo at mouseover button validation