Check for standard WP admin page before attaching action.

standard-wp-admin-check.php

<?php

/*
Plugin Name: Standard WP Admin Page Check
Description: Example code.
Version: 1.0
Author: Alex King
Author URI: http://alexking.org
*/

function ak_wp_admin_standard_page_test() {

?>
<script type="text/javascript">
alert('This is a standard WP admin page.');
</script>
<?php

}
if ( !defined( 'IFRAME_REQUEST' ) ) {
	add_action( 'admin_head', 'ak_wp_admin_standard_page_test' );
}

?>