<div style="border: 1px solid #ccc; border-radius: 5px; padding: 1px; margin: 20px;">
  <textarea id="mytextarea"></textarea>
</div>

tinymce.init({
    selector: "#mytextarea",
    menubar: false,
    toolbar_location: "bottom",
    plugins: "link lists emoticons image autoresize",
    toolbar: "bold italic strikethrough link numlist bullist blockquote emoticons image | mySendButton",
	setup: function (editor) {
    editor.ui.registry.addButton("mySendButton", {
      tooltip: "Send Message",
	  text: "Send",
      onAction: function () {
        alert(editor.getContent());
		editor.resetContent();
      }
    });
  },
  skin: "borderless",
  icons: "small",
  statusbar: false,
  autoresize_bottom_margin: 0,
  max_height: 500,
  placeholder: "Enter message . . ."
});