function displaySelect(isDisplay){
  var allselect = document.getElementsByTagName("select");
  if(isDisplay=="0"){
    for(i=0;i<allselect.length;i++){
      allselect[i].style.visibility = "hidden";
    }
  }else{
    for(i=0;i<allselect.length;i++){
      allselect[i].style.visibility = "visible";
    }
  }
}