function submitform() {
  var searchterm = document.form1.q.value;
  if (IsNumeric(searchterm) == true && searchterm.length > 4) {
    document.form1.action = 'http://ptplv.ais.ucla.edu/go/' + searchterm + '/';
    document.form1.method = 'post';
  }
  else {
    document.form1.action = 'http://gsa1.ais.ucla.edu/search';
  }
  document.form1.submit();
}

function IsNumeric(str) {
  var strValidChars = "0123456789.-";
  var strChar;

  if (str.length == 0) return false;

  for (i = 0; i < str.length; i++) {
    strChar = str.charAt(i);
    if (strValidChars.indexOf(strChar) == -1) return false;
  }

  return true;
}