Lost parameters during form submission to open a pdf in new window

My java webApp (struts2 and jQuery) has a jsp with a form:

<s:form id="theForm" action="stampaPosizioneFinanziaria" target="_new">

and a jQuery button:

<a id="stampaPerCliente">Stampa standard</a> // rendere by $('#tampaPerCliente').button();

On button click:

$('#stampaPerCliente').click(function(){ avviaStampa(0); });

..开发者_开发百科.

function avviaStampa(tipoStampa) {
  $('[name=tipoStampa]').val(tipoStampa); // I set a hidden field
  $('#theForm').submit();
      // tried document.forms[0].submit(); too, same behavior.
}

So, the new page opened (the form target is _new) calls an action that read the paramters form and displays a pdf. Everything works fine BUT: on IE when I click the button first time it works, second time doesn't, third time does and so on. The 'doesn't work' means the action has every input parameters null! I monitored the request and on IE there aren't request parameters! (even times, not odd times!) It works fine on Chrome and FF.

Help please.

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I solved using GET method for submission:

<s:form id="theForm" action="stampaPosizioneFinanziaria" target="_new" method="GET">

The POST method (default for struts2 s:form) caused this issue (?!!!?).