How to send form using POST method and use showModalDialog at the same time (complete question)

[JEL]

Hi everybody,

i'm writing a function to post a form and at the same time to open a
modal or non-modal window (this is currently for IE 5.5 only)
i already found a solution for the non-modal stuff and it works well,
the pb is for the modal version of the function
any idea ?
i have created my own adresseURL (concating the p_commande and all the
attributes of my form) and passing it to the dialogArguments of
showModalDialog and it works well for 'little' forms because it's a
GET method and i have too many attributes in my form so i need to use
a POST method (which is the default method of my form)
many thanks in advance

function js_openWindow(p_commande,p_winWidth,p_winHeight,p_isModal,p_nameForm,p_isToNavigate){
if (p_isModal){
// i want here my showModalDialog
}else{
var form = eval(p_nameForm);
var tempTarget = form.target;
var tempAction = form.action;
form.target = 'KJ';
form.action = p_commande;
p_windowProperties="width=" +p_winWidth +",height=" +
p_winHeight + ",dependent,status=no,toolbar=no,resizable=no,scrollbars=no"
newWindow=window.open('','KJ',p_windowProperties);
form.submit();
form.target = tempTarget;
form.action = tempAction;
newWindow.focus();
}