Get post id from meta key and value

Get post id from meta key and value.php

<?php  
/**
   * Get post id from meta key and value
   * @param string $key
   * @param mixed $value
   * @return int|bool
   * @author David M&aring;rtensson <[email protected]>
   */
  function get_post_id_by_meta($key, $value) {
    global $wpdb;
    $meta = $wpdb->get_results("SELECT * FROM `".$wpdb->postmeta."` WHERE meta_key='".$wpdb->escape($key)."' AND meta_value='".$wpdb->escape($value)."'");
    if (is_array($meta) && !empty($meta) && isset($meta[0])) {
      $meta = $meta[0];
    }   
    if (is_object($meta)) {
      return $meta->post_id;
    } else {
      return false;
    }
  }