Plugin error in wp_debug mode

Hi, first off just wanted to thank you for your work on this awesome little plugin.

I’m getting an error when updating the plugin option with wp_debug mode turned on.

The error is as follows:

Notice: Undefined index: textarea_one in /path-shortened/wp-content/plugins/format-media-titles/format-media-titles.php on line 140

Notice: Undefined index: txt_one in /path-shortened/wp-content/plugins/format-media-titles/format-media-titles.php on line 143

Warning: Cannot modify header information - headers already sent by (output started at /path-shortened/wp-content/plugins/format-media-titles/format-media-titles.php:140) in /path-shortened/wp-includes/pluggable.php on line 1121

When I update your code to check for a value being set all of the errors disappear. Here is my updated code:

if (isset( $input['textarea_one'] )) {
		$input['textarea_one'] =  wp_filter_nohtml_kses($input['textarea_one']); // Sanitize textarea input (strip html tags, and escape characters)
	}
	if (isset($input['txt_one'] )) {
		$input['txt_one'] =  wp_filter_nohtml_kses($input['txt_one']); // Sanitize textbox input (strip html tags, and escape characters)
	}

Just wanted to give you a heads up.

https://wordpress.org/plugins/format-media-titles/