//只能输入数字
function isregname( checkobj)
   {
     var checkOK = "0123456789.";
     //-_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
     var checkStr = checkobj;
     var allValid = true;
     var decPoints = 0;
     
     for (i = 0;  i < checkStr.length;  i++)
     {
      ch = checkStr.charAt(i);
      for (j = 0;  j < checkOK.length;  j++)
      if (ch == checkOK.charAt(j))
      break;
       if (j == checkOK.length)
       {
        allValid = false;
        break;
       } 
      }
     return (allValid)
    }
/**
* 得到文件的后缀名
* oFile为file控件对象
*/
function getFilePostfix(oFile)
{
    if(oFile == null)
        return null;
    var pattern = /(.*)\.(.*)$/gi;
    if(typeof(oFile) == "object")
    {
        if(oFile.value == null || oFile.value == "")
            return null;
        var arr = pattern.exec(oFile.value);
        return RegExp.$2;
    }
    else if(typeof(oFile) == "string")
    {
        var arr = pattern.exec(oFile);
        return RegExp.$2;
    }
    else
        return null;
}
//~~~
/**
* 计算字符串的长度，一个汉字两个字符
*/
/*--------------------------------- chinese --------------------------------------*/
function textCounter(field,maxlimit) 
 {
      var str="";
      var allValid = true;
      str=field.value;
      str=str.replace(/[^\x00-\xff]/g,"**"); 
      
      if (str.length > maxlimit)
      {
           //field.value=getByteOfNum(field.value,maxlimit);
           return false;
      }
     return (allValid)
 }
 
 function getByteOfNum(val, num)
 {
  var ch,bytenum=0;
  var rs = "";
  var pt = /[^\x00-\xff]/;
  for (var i=0; i < num; i++)
  {
   ch = val.substr(i, 1);
   if (ch.match(pt))
   {
    bytenum += 2;
    if (bytenum > num)
    {
     return rs;
    }
   }else
   {
    bytenum += 1;
   }
   rs += ch;
   if (bytenum == num)
   {
    return rs;
   }
  }
  return rs;
 }