problem with javascript

[meuline]

Hello,

In my web page, I have an Input field with two events (onkeyup and onchange) calling a javascript function.
This javascript checks if the size’s value is 5. If so, the form is submit and the same screen is display.

My problem : When I made a record, if I write 5 characters, the event is not recorded.
Remark : If I write 2 characters and I quit the field it’s OK.


My input field

Code:

<input type="text" name="codePostal" onkeyup="javascript:cpAction();" onchange="javascript:cpAction();">

My javascript

Code:

function cpAction(){
            var cp = formulaire.elements['codePostal'].value
            if( ((cp.length == 5) && (estValideCodePostal(cp))) || (cp.length == 0) ){
                        aValider = false;
                        formulaire.elements['reqCode'].value='display';
                        formulaire.submit();
            }
}

Thank's