Opening a new tab on PHP

Question

I have a simple form:

<form id="frm" action="process.php" method="post">
    <input type="text" id="shortcut" name="shortcut" />
</form>

In process.php:

$gomenu = $_POST['shortcut'];
if(strpos($gomenu, "/") === 0) {
    //if $gomenu contains `/`, then it should open in new tab
    header('Location: newTab.php'); //--> How to open this into a new tab?
} else {
    header('Location: somePage.php'); //--> Redirect to somePage.php on the same tab
}

When the shortcut contains value of /, then it should be redirect to a new tab, else the same tab. How to do that? I know it's impossible to do that by using header();, but I have no idea how to do that. Any ideas? Thanks.

PS: The form is intended to fill by a menu code, then it has to redirect the page based on the menu code filled on shortcut (as in SAP). But if it contains a specific prefix, a different way should be implemented.

---

UPDATE

Above the form, I've added this script:

<script>
    $("#frm").ajaxForm({
        url: 'process.php', type: 'post'
    });
</script>

And on the process.php:

$gomenu = $_POST['shortcut'];
if(strpos($gomenu, "/") === 0) {
    print   "<script>
                 window.open('newTab.php', '_newtab');
             </script>";
} else {
    header('Location: somePage.php');
}

But then it opened in a new pop-up window. How to open it on the newtab?

---

ANSWER (@fedmich's answer)

        $(document).ready(function () {
            $('frm#frm').submit(function(){
                var open_new_tab = false;
                var v = $('#shortcut').val();
                if(v.match('/') ){
                    open_new_tab = true;
                }

                if ( open_new_tab ) {
                    $('frm#frm').attr('target', '_blank');
                } else {
                    $('frm#frm').attr('target', '_self');
                }
            });
        });

Solution 1

I think you could do it this way, put the target blank by default.

<form id="frm" action="process.php" method="post" target="_blank">

</form>

then when submitting on the form submit() and modify & navigate away if you need to. you could just use javascript before submitting, change the action or target attributes

http://jsfiddle.net/fedmich/9kpMU

$('form#frm').submit(function(){
    var open_new_tab = false;
    var v = $('#shortcut').val();
    if(v.match('/') ){
        open_new_tab = true;
    }

    if ( open_new_tab ) {
        alert('opening to new tab');
        $('form#frm').attr('target', '_blank');
        $('form#frm').attr('action', 'http://www.youtube.com');
    }
    else{
        alert('opening to self_page');
        $('form#frm').attr('target', '_self');
        $('form#frm').attr('action', 'http://www.yahoo.com');
    }
});

Solution 2

Submit your form via AJAX, send the new URL in the response from PHP, and use JavaScript to open your new window, if your PHP script specifies that it should.