function showletters(){
  document.getElementById("LetterList").style.display="inline";
  document.getElementById("ByName").outerHTML='<li id=ByName class="selected"><div class="selend">по названию</div></li>';
  closemetro();
}

function closeletters(){
  document.getElementById("ByName").outerHTML='<li id=ByName><a href="#" onclick=\'showletters(); return false;\'>по названию</a></li>';
  document.getElementById("LetterList").style.display="none";
}

function showmetro(){
  document.getElementById("Metro").style.display="inline";
  document.getElementById("ByMetro").outerHTML='<li id=ByMetro class="selected"><div class="selend">по метро</div></li>';
  closeletters();
}

function closemetro(){
  document.getElementById("ByMetro").outerHTML='<li id=ByMetro><a href="#" onclick=\'showmetro(); return false;\'>по метро</a></li>';
  document.getElementById("Metro").style.display="none";
}


function numbersonly(myfield, e, dec) {
  var key;
  var keychar;

  if (window.event)
    key = window.event.keyCode;
  else if (e)
    key = e.which;
  else
    return true;
  keychar = String.fromCharCode(key);

  // control keys
  if ((key==null) || (key==0) || (key==8) || (key==9) || (key==13) || (key==27) || (key==37) || (key==39) || (key==46) )
    return true;
  // numbers
  else if ((("0123456789").indexOf(keychar) > -1))
    return true;

  // decimal point jump
  else if (dec && (keychar == ".")) {
    myfield.form.elements[dec].focus();
    return false;
  } else
    return false;
}