function isemail (s)
{
         var regu = "^(([0-9a-zA-Z]+)|([0-9a-zA-Z]+[_.0-9a-zA-Z-]*[0-9a-zA-Z]+))@([a-zA-Z0-9-]+[.])+([a-zA-Z]{2}|net|NET|com|COM|gov|GOV|mil|MIL|org|ORG|edu|EDU|int|INT)$"
         var re = new RegExp(regu);
         if (s.search(re) != -1) {
               return true;
         } else {
               return false;
         }
}

function isurl (s)
{
         var regu = "([a-zA-Z0-9-]+[.])+([a-zA-Z]{2}|net|NET|com|COM|gov|GOV|mil|MIL|org|ORG|edu|EDU|int|INT)"
         var re = new RegExp(regu);
         if (s.search(re) != -1) {
               return true;
         } else {
               return false;
         }
}

function isusername (s)
{
         var regu = "^([_0-9a-zA-Z@.-]*)$"
         var re = new RegExp(regu);
         if (s.search(re) != -1) {
               return true;
         } else {
               return false;
         }
}

function Jtrim(str)
{//去字符串首尾空格.
        var i = 0;
        var len = str.length;
        if ( str == "" ) return( str );
        j = len -1;
        flagbegin = true;
        flagend = true;
        while ( flagbegin == true && i< len)
        {
           if ( str.charAt(i) == " " )
                {
                        i=i+1;
                        flagbegin=true;
                }
                else
                {
                        flagbegin=false;
                }
        }

        while  (flagend== true && j>=0)
        {
            if (str.charAt(j)==" ")
                {
                        j=j-1;
                        flagend=true;
                }
                else
                {
                        flagend=false;
                }
        }

        if ( i > j ) return ("")

        trimstr = str.substring(i,j+1);
        return trimstr;
}

function isValidDate( year, month, day )
{
  year  = parseInt(year,10);
  month = parseInt(month,10);
  day   = parseInt(day,10);

  if (( month==4) || (month==6) || (month==9) || (month==11) )
  {
    if (( day < 1) || (day > 30) )
      return ("日期在1 - 30之间");
  }
  else
  { if ( month!=2 )
    {
      if ( (day < 1) || (day > 31 ))
         return ("日期在1 - 31之间");
    }
    else
    { // month == 2
      if ( ( year % 100 ) != 0 && (year % 4 == 0) || ( year % 100 ) == 0 && ( year % 400) == 0 )
      { 
        if ( day > 29 )
           return ("日期在1 - 29之间");
      }
      else
      {
        if ( day > 28 )
          return ("日期在1 - 28之间");
      }
    }
  }
  return (true);
}

function isDigital(checkStr)
{//是数字
  checkStr = Jtrim(checkStr);
  var regu = "^([0-9]*)$"
  var re = new RegExp(regu);
  if (checkStr.search(re) != -1) {
    return true;
  } else {
    return false;
  }
}

function inDigital5(checkStr)
{//含5个数字以上
  var regu = "([０-９]{5,}|[0-9]{5,})"
  var re = new RegExp(regu);
  if (checkStr.search(re) != -1) {
    return true;
  } else {
    return false;
  }
}

function isTel(checkStr)
{
  var regu = "^(([0-9-/\(\)]*,*)*)$"
  var re = new RegExp(regu);
  if (checkStr.search(re) != -1) {
    return true;
  } else {
    return false;
  }
}

function DateCompare(YearFrom, MonthFrom, YearTo, MonthTo)
{  YearFrom  = parseInt(YearFrom,10);
   MonthFrom = parseInt(MonthFrom,10);
   YearTo    = parseInt(YearTo,10);
   MonthTo   = parseInt(MonthTo,10);

   if (YearFrom > YearTo)
     { return false;}
   else
   {  if (YearFrom == YearTo)
      {  if (MonthFrom > MonthTo)
            return false;
      }
   }
   return true;
}