// 验证输入的消息
function checkStr(wordnumber)
{
  var message = document.sendcomment.content.value;
  var wordNum = wordnumber;
  var spareStr = wordNum - message.length;
  if(message.length > wordNum)
  {
      document.getElementById('spareStr').className = "requiredField";
      if(navigator.userAgent.indexOf("Firefox") > 0)
      {
        document.getElementById('spareStr').textContent = "<font color='red'>已经超出 <b>"+(message.length - wordNum)+"</b> 个字</font>";  

      }
      else
      {
        document.getElementById('spareStr').innerHTML = "<font color='red'>已经超出 <b>"+(message.length - wordNum)+"</b> 个字</font>";  
      }
  }
  /*
  else if(message.length == wordNum)
  {
      document.getElementById('spareStr').className = "";
      if(navigator.userAgent.indexOf("Firefox") > 0)
      {
        document.getElementById('spareStr').textContent = "可以输入 <b>"+ wordNum +"</b> 个字";
      }
      else
      {
        document.getElementById('spareStr').innerHTML = "可以输入 <b>"+ wordNum +"</b> 个字";
      }
  }
  */
  else if(message.length >= 1)
  {
    document.getElementById('spareStr').className = "";
    if(navigator.userAgent.indexOf("Firefox") > 0)
      {
        document.getElementById('spareStr').textContent = "可以输入 <b>"+spareStr+"</b> 个字";
      }
      else
      {
        document.getElementById('spareStr').innerHTML = "可以输入 <b>"+spareStr+"</b> 个字";
      }
  }
  else if(message.length == 0)
  {
    document.getElementById('spareStr').className = "";
    if(navigator.userAgent.indexOf("Firefox") > 0)
      {
        document.getElementById('spareStr').textContent = "可以输入 <b>"+ wordNum +"</b> 个字";
      }
      else
      {
        document.getElementById('spareStr').innerHTML = "可以输入 <b>"+ wordNum +"</b> 个字";
      }
  }
}