onload = function() { 

  var strUA = "";
  strUA = navigator.userAgent.toLowerCase();

        if(strUA.indexOf("safari") != -1){
    var h_margin = 0;

  }else if(strUA.indexOf("firefox") != -1){
    var h_margin = 0;

  }else if(strUA.indexOf("opera") != -1){
    var h_margin = 0;

  }else if(strUA.indexOf("netscape") != -1){
    var h_margin = 0;

  }else if(strUA.indexOf("msie") != -1){
    var h_margin = 14;

  }else if(strUA.indexOf("mozilla/4") != -1){
    var h_margin = 0;
  }

//document.getElementsByTagName("iframe")[0].height = leftmenu.document.getElementsByTagName("span")[0].offsetHeight + 35; 
document.getElementsByTagName("iframe")[0].height = leftmenu.document.getElementsByTagName("span")[0].offsetHeight + h_margin; 
document.getElementsByTagName("iframe")[0].style.visibility = "visible"; 
}