Søgebox til søgning af tekst i en ramme

Jeg har på internettet fundet et søgeprogram som søger et ord på den samme side som søgeboksen findes. Hvordan får jeg den til at søge på et ord i en anden ramme?
Programmet ser sådan ud:<script language=\"JavaScript\">

/*
Find In Page Script-
By Mike Hall (MHall75819@aol.com)
Permission granted to Dynamicdrive.com to feature script in archive
For full source code, visit http://dynamicdrive.com
*/

var NS4 = (document.layers);    // Which browser?
var IE4 = (document.all);

var win = window;    // window to search.
var n  = 0;

function findInPage(str) {

  var txt, i, found;

  if (str == \"\")
    return false;

  // Find next occurance of the given string on the page, wrap around to the
  // start of the page if necessary.

  if (NS4) {

    // Look for match starting at the current point. If not found, rewind
    // back to the first match.

    if (!win.find(str))
      while(win.find(str, false, true))
        n++;
    else
      n++;

    // If not found in either direction, give message.

    if (n == 0)
      alert(\"Not found.\");
  }

  if (IE4) {
    txt = win.document.body.createTextRange();

    // Find the nth match from the top of the page.

    for (i = 0; i <= n && (found = txt.findText(str)) != false; i++) {
      txt.moveStart(\"character\", 1);
      txt.moveEnd(\"textedit\");
    }

    // If found, mark it and scroll it into view.

    if (found) {
      txt.moveStart(\"character\", -1);
      txt.findText(str);
      txt.select();
      txt.scrollIntoView();
      n++;
    }

    // Otherwise, start over at the top of the page and find first match.

    else {
      if (n > 0) {
        n = 0;
        findInPage(str);
      }

      // Not found anywhere, give message.

      else
        alert(\"Not found.\");
    }
  }

  return false;
}

</script>


<form name=\"search\" onSubmit=\"return findInPage(this.string.value);\">
  <font size=\"3\"><p><input name=\"string\" type=\"text\" size=\"15\" onChange=\"n = 0;\"></font> <input
  type=\"submit\" value=\"Find\"> </p>
</form>