function check_js($var)

Please add a global function check_js() to drupal. I found a nice code snippet in common.inc used inside the function drupal_to_js.

function check_js($var) {
  // alters strings to be HTML-safe strings, i.e. with <, > and & escaped
  return '"'. str_replace(array("\r", "\n", "<", ">", "&"),
                          array('\r', '\n', '\x3c', '\x3e', '\x26'),
                          addslashes($var)) .'"';
}

Now as a workaround i created such a function with a different name for a module, but it will be better to have it implemented as a common function for easy reuse.