E-mail selected pages

My form uses javascript to e-mail the document as a PDF. The script does not allow the form to be sent if a checkbox has not been activated. My form is five pages long: when submit is clicked I want to email only the first three pages.

How can I do that?

var check = xfa.resolveNode("CheckBox3");

var url_address = "mailto:test [at] abc [dot] combody=Send this email to submit your proposal. Add notes if desired.";

var doc = event.target;

if(check.rawValue == 0){

app.alert("Your proposal will not be accepted if you have not checked your acceptance.");

}else{

var form_format = "PDF";
doc.submitForm({ cURL: url_address, cSubmitAs: form_format} );
}