function ChgTextSize(flg) {
  
  // フォントサイズ用
  var size = "";
  
  // 画像ファイル用
  var btn_big = "";
  var btn_middle = "";
  var btn_small = "";
  
  // Attribute用フラグ
  var attr_big = "";
  var attr_middle = "";
  var attr_small = "";
  
  
  if (flg == "big") {
    
    // 文字サイズ“大”
    
    size = "font-size:103%;";
    
    btn_big = "/images/renew/header_fontsize_b_btn_on.gif";
    btn_middle = "/images/renew/header_fontsize_m_btn_off.gif";
    btn_small = "/images/renew/header_fontsize_s_btn_off.gif";
    
    attr_big = 0;
    attr_middle = 1;
    attr_small = 1;
    
  } else if (flg == "middle") {
    
    // 文字サイズ“中”
    
    size = "font-size:93%;";
    
    btn_big = "/images/renew/header_fontsize_b_btn_off.gif";
    btn_middle = "/images/renew/header_fontsize_m_btn_on.gif";
    btn_small = "/images/renew/header_fontsize_s_btn_off.gif";
    
    attr_big = 1;
    attr_middle = 0;
    attr_small = 1;
    
  } else if (flg == "small"){
    
    // 文字サイズ“小”
    
    size = "font-size:81%;";
    
    btn_big = "/images/renew/header_fontsize_b_btn_off.gif";
    btn_middle = "/images/renew/header_fontsize_m_btn_off.gif";
    btn_small = "/images/renew/header_fontsize_s_btn_on.gif";
    
    attr_big = 1;
    attr_middle = 1;
    attr_small = 0;
  }

  if (document.all) {
    
    document.all("new_container").style.cssText = size;
    
    document.all("img_big").src = btn_big;
    document.all("img_middle").src = btn_middle;
    document.all("img_small").src = btn_small;
    
    document.all("img_big").onmouseover = attr_big <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_off.", "_on."));
    };
    document.all("img_big").onmouseout = attr_big <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_on.", "_off."));
    };
    
    document.all("img_middle").onmouseover = attr_middle <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_off.", "_on."));
    };
    document.all("img_middle").onmouseout = attr_middle <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_on.", "_off."));
    };
    
    document.all("img_small").onmouseover = attr_small <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_off.", "_on."));
    };
    document.all("img_small").onmouseout = attr_small <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_on.", "_off."));
    };
    
  } else if(document.getElementById) {
    
    document.getElementById("new_container").setAttribute("style", size);
    
    document.getElementById("img_big").src = btn_big;
    document.getElementById("img_middle").src = btn_middle;
    document.getElementById("img_small").src = btn_small;
    
    document.getElementById("img_big").onmouseover = attr_big <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_off.", "_on."));
    };
    document.getElementById("img_big").onmouseout = attr_big <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_on.", "_off."));
    };
    
    document.getElementById("img_middle").onmouseover = attr_middle <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_off.", "_on."));
    };
    document.getElementById("img_middle").onmouseout = attr_middle <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_on.", "_off."));
    };
    
    document.getElementById("img_small").onmouseover = attr_small <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_off.", "_on."));
    };
    document.getElementById("img_small").onmouseout = attr_small <= 0 ? null : function() {
      this.setAttribute("src", this.getAttribute("src").replace("_on.", "_off."));
    };
    
  } else {
    
    if(flg) {
        alert("お使いのブラウザではサイズ変更に対応しておりません。");
    }
  }
}