configuring a button

Greetings, I'm opening a window with "Runner.displayPopup" in "Client Before" Button, using the following script:
var win = Runner.displayPopup( {

url: "tbformapago_add.php",

header: 'Añadir nueva forma de pago',

footer: '<a href="#" onclick="window.win.close();">Close window</a>',

afterCreate: function(win) {

window.win = win;

}

});
then in Server execute a series of php instructions, but I need these instructions to be executed after closing the window that was opened in the previous event, however when opening the window, the execution continues until the end (Client After).

How do I add a pause until I close the window I opened at the beginning?