Using wp_editor in "own" Plugin

Hi guys,I’m trying to get this working for a few hours now.
What I was trying to achieve was a plugin where the user could set text into a global variable,so I can post that variable on another page.
wp_editor came in handy since the user also can format everything he writes.
But I can’t get it to work,it doesn’t save text into that post after hitting the Save Button.
Maybe I’m totally wrong and it doesn’t need a post or maybe saving can be solved somewhat different. Maybe my Idea was totally wrong and somebody knows a way better Idea?
Any suggestions are Welcomed.
Thanks in advance for your help!

<?php
// Specify Hooks/Filters
register_activation_hook(__FILE__, 'add_defaults_fn');
add_action('admin_init', 'sampleoptions_init_fn' );
add_action('admin_menu', 'sampleoptions_add_page_fn');
$options = get_option('plugin_options');
global $test;
global $inhalt;

		if($options['option_set1']=="Weiss"){
                        $test='<div class="box basic">';
                }
                if($options['option_set1']=="Durchsichtig"){
                        $test='<div class="box gradient">';
                }

// Define default option settings

function add_defaults_fn() {
	$tmp = get_option('plugin_options');
}

// Register our settings. Add the settings section, and settings fields
function sampleoptions_init_fn(){
	register_setting('plugin_options', 'plugin_options', 'plugin_options_validate' );
	add_settings_section('main_section', 'Haupteinstellungen', 'section_text_fn', __FILE__);
	//add_settings_field('plugin_textarea_string', 'Ihr Text:', 'setting_textarea_fn', __FILE__, 'main_section');
	add_settings_field('radio_buttons', 'Hintergrund:', 'setting_radio_fn', __FILE__, 'main_section');

}

// Add sub page to the Settings Menu
function sampleoptions_add_page_fn() {
	add_options_page('FrontQuote', 'FrontQuote', 'administrator', __FILE__, 'options_page_fn');
}

// ************************************************************************************************************

// Callback functions

// Section HTML, displayed before the first option
function  section_text_fn() {
	echo '<p></p>';
}

// TEXTAREA - Name: plugin_options[text_area]
function setting_textarea_fn() {
	$options = get_option('plugin_options');
	echo "<textarea id='plugin_textarea_string' name='plugin_options[text_area]' rows='7' cols='50' type='textarea'>{$options['text_area']}</textarea>";

}

// RADIO-BUTTON - Name: plugin_options[option_set1]
function setting_radio_fn() {
	$options = get_option('plugin_options');
	$items = array("Durchsichtig", "Weiss");
	foreach($items as $item) {
		$checked = ($options['option_set1']==$item) ? ' checked="checked" ' : '';
		echo "<label><input ".$checked." value='$item' name='plugin_options[option_set1]' type='radio' /> $item</label><br />";
	}
}

// Display the admin options page
function options_page_fn() {
?>
	<div class="wrap">
		<div class="icon32" id="icon-options-general"><br></div>
		<h2>FrontQuote</h2>
		Einstellen, Aktiviren/Deaktivieren und Administrieren des Zitats auf der Homepage
		<form action="options.php" method="post">
		<?php settings_fields('plugin_options'); ?>
		<?php do_settings_sections(__FILE__); ?>
		<?php
			$options = get_option('plugin_options');
			var_dump($options);

		?>

	<?php
	$options = get_option('plugin_options');
	$post = get_post( 1850, 'OBJECT' );

	$settings = array(

		' textarea_name' => 'somecontent',

	);

	wp_editor($post->post_content, 'textarea02', $settings );
	update_option(1850 ,$_POST[1850]);

?>	

		<p class="submit">
			<input name="Submit" type="submit" class="button-primary" value="<?php esc_attr_e('Save Changes'); ?>" />
		</p>
		</form>
	</div>
<?php
}

// Validate user data for some/all of your input fields
function plugin_options_validate($input) {
	// Check our textbox option field contains no HTML tags - if so strip them out
	$input['text_string'] =  wp_filter_nohtml_kses($input['text_string']);
	return $input; // return validated input
}