How to enable writing code like js in tinymce editor?

Question

I'm using tinymce editor in my entire website in which user can write ifames or javascript code and save/update that. But whenever I write js code in it, it hides that. How can I enable tinymce to allow users to write anything in it?

Version: 4.3.10.

http://prntscr.com/dk3a22

as you can see in screenshot, only thing that is left behind is html code. other is removed as soon as in press OK button.

tinymce.init({
selector: "textarea",
allow_script_urls: true,
extended_valid_elements: 'span,script[language|type|src]',
browser_spellcheck: true,
force_br_newlines: true,
force_p_newlines: false,
forced_root_block: '',
font_formats: 'Arial=arial,helvetica,sans-serif;Courier New=courier new,courier,monospace;AkrutiKndPadmini=Akpdmi-n;Comic Sans MS=comic sans ms,sans-serif;Times New Roman=times new roman,times;',
fontsize_formats: '8pt 10pt 12pt 14pt 18pt 24pt 36pt',
plugins: ["textcolor", "advlist autolink lists link image charmap print preview anchor", "searchreplace visualblocks code fullscreen", "insertdatetime media table paste"],
toolbar: "fontselect | fontsizeselect | forecolor backcolor | insertfile undo redo | styleselect | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | link image",
height: "200",