var defaultValue = "メールアドレスを記入してください";
function regEnter() {
  var email = window.document.reg.rdemail;
  if (email.value == defaultValue) {
    email.value = "";
  }
  email.className = "emailfilled";
}


function regExit() {
  var email = window.document.reg.rdemail;
  if ((email.value == defaultValue) || (email.value == "")) {
    email.value = defaultValue;
    email.className = "emailempty";
  }
}


/**
 * アンケートの自由記入欄の高さを増やす
 */
function expand_textarea(id) {
  document.getElementById(id).rows += 8;
}