wordpress media uploader window size - wordpress

Question

i got one issue that im stacked on.
Im running the media uploader window from a colorbox modal window, which i set to 90% width, and inside i have button which trigger the media uploader (opens second window).
but when i trigger it, it everytime opens smaller modal window than the parent colorbox modal.
i think the problem is that my first window is an Iframe and when i trigger another modal, it takes the iframe as main window and by some percentage it makes the second window smaller. this could fix if i know where to set, that the second window should be 100%.
Do you know where can i set the width and height for the window with media uploader? i tried with the "40" value, but it doesnt work. i cant find no documentation for this.
thanks for reply.
screenshot here: screencast link
my code is
var file_frame1;
jQuery('#mxn_button_add_img1').on('click', function(event) {
event.preventDefault();
// If the media frame already exists, reopen it.
if (file_frame1) {
file_frame1.open();
return;
}
// Create the media frame.
file_frame1 = wp.media.frames.file_frame = wp.media({
title: jQuery(this).data('uploader_title'),
width: 40,
button: {
text: jQuery(this).data('uploader_button_text'),
},
multiple: false // Set to true to allow multiple files to be selected
});
// When an image is selected, run a callback.
// When an image is selected, run a callback.
file_frame1.on('select', function() {
var selection = file_frame1.state().get('selection');
selection.map(function(attachment) {
attachment = attachment.toJSON();
jQuery('#mxn_input_img1').val(attachment.url);
jQuery('#mxn_post_img1').attr('src', attachment.url);
return false;
});
});
});