function trim(str, size) {
  if(str.length > size){
    var cutstring = str.substring(0, size);
    var byte = countByte(cutstring);
    var tmp = "";
    if (byte < size*2) {
       for(k=0; k < (size*2-byte)*2; k++){
         tmp = str.substring(0,size + k);
         if (countByte(tmp) >= size*2) {
           break;
         }
       }
    }
    if(tmp){
      return tmp + tail;
    } else {
      return str.substring(0, size) + tail;
    }
  } else {
    return str;
  }
}
 
function countByte(str) {
  var byte = 0;
  for (j=0; j < str.length; j++) {
    str.charCodeAt(j) < 0x100 ? byte++ : byte += 2;
  }
  return byte;
}

function study_open_close() {
  $(function(){$(".open_close").css("display","block");});
  for (i=97; i<=118; i++) {
    (function (key) {
      $(function(){
         $("div." + key + "_003").css("display","none");
         $("p#" + key + "_001_caption").text(trim($("p#" + key + "_003_body").text(), size_exp[key] || size_default));
         $("li." + key + "_005").toggle(
          function(){
            $("div." + key + "_003").css("display","block");
            $("p#" + key + "_001_caption").css("display","none");
          },
          function(){
            $("div." + key + "_003").css("display","none");
            $("p#" + key + "_001_caption").css("display","block");
         })
      });
    }(String.fromCharCode(i)));
  }
}