how to disable tinymce editor

I want to disable tinymce editor using Javascript. Actually, I have two radio buttons: 1) On & 2) Off.

When the user selects the Off radio button, my tinymce editor should be readonly/disabled & when the user selects the On radio button, my tinymce editor should be enabled.

How can I achieve that?

EDITED:- (As it is not working in IE8)

tinyMCE.init({
    force_p_newlines : false,
    force_br_newlines : false,
    forced_root_block : false,
    convert_newlines_to_brs: false,
    // Not to add br elements.
    remove_linebreaks : true,

    mode : "textareas",
    theme : "advanced",
    plugins : "safari",
    convert_urls : false,
    width : "560",
    height : "15",
    theme_advanced_buttons1 : "fontselect,fontsizeselect, separator, bold,italic,underline,separator,forecolor,backcolor,justifyleft,justifycenter,justifyright,justifyfull",

    theme_advanced_buttons2 : "",
    theme_advanced_buttons3 : "",
    theme_advanced_toolbar_location : "top",
    theme_advanced_toolbar_align : "left", extended_valid_elements : "a[name|href|target|title|onclick],img[class|src| border=0|alt|title|hspace|vspace|width|height|align|onmouseover|onmouseout|name], hr[class|width|size|noshade],font[face|size|color|style],span[class|align|style]"
});

This code is used to disable:

function tinymce_state(id, disable){
    var state = (disable==true)? 'Off' : 'On'
    tinymce.get(id).getDoc().designMode = state;
    tinymce.get(id).controlManager.get('fontselect').setDisabled(disable);
    tinymce.get(id).controlManager.get('fontsizeselect').setDisabled(disable);
    tinymce.get(id).controlManager.get('bold').setDisabled(disable);
    tinymce.get(id).controlManager.get('italic').setDisabled(disable);
    tinymce.get(id).controlManager.get('underline').setDisabled(disable);
    tinymce.get(id).controlManager.get('forecolor').setDisabled(disable);
    tinymce.get(id).controlManager.get('backcolor').setDisabled(disable);
    tinymce.get(id).controlManager.get('justifyleft').setDisabled(disable);
    tinymce.get(id).controlManager.get('justifycenter').setDisabled(disable);
    tinymce.get(id).controlManager.get('justifyright').setDisabled(disable);
    tinymce.get(id).controlManager.get('justifyfull').setDisabled(disable);
}

Solution

You may use the following to block input in the editor:

// blockeditor input
tinymce.get('editor_id').getDoc().designMode = 'Off'; // switches editable off

// turn it on again
tinymce.get('editor_id').getDoc().designMode = 'On'; // switches editable on

You still need to find a way to block the tinymce UI. You could deactivate EACH control you have loaded (in the init function) using a line for EACH one of them

// example control bold
tinymce.get('editor_id').controlManager.get('bold').setDisabled(true);

// turn it on again
tinymce.get('editor_id').controlManager.get('bold').setDisabled(false);

EDIT:

You could change the contenteditable property of your rtes iframe body. Downside will be that you will have to disable the tinymce UI (buttons) seperatly

// disable contenteditable
tinymce.get('editor_id').getBody().setAttribute('contenteditable', 'false');

// enable contenteditable
tinymce.get('editor_id').getBody().setAttribute('contenteditable', 'true');