//清除字符串前后的空格
function trim(data) {
	if(data == null) return "";
	return data.replace(/(^\s*)|(\s*$)/g, "");
}

function isChinese(temp)  
{  
 	var re = /[^\u4e00-\u9fa5]/;  
 	if(re.test(temp)) return false;  
 	return true;  
}  

function isEmail(data) {
	data = trim(data);	
	if(data.length == 0) return false;
	var pattern = /^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$/;
 	if(data.match(pattern)==null){
 		return false;
 	} else {
 		return true;
 	}	
}

function   isLeapYear(year) { 
	if((year%4==0&&year%100!=0)||(year%400==0))     
	{     
		return   true;     
	}       
	return   false;     
}     

//判断时间是否正确   

function isDate(str){   
	var   datetime;   
	var   year,month,day;    
	datetime = trim(str);
	if(datetime.length != 10) return false;
	year = datetime.substring(0,4);   
	month=datetime.substring(5,7);   
	day=datetime.substring(8,10);   

	if(isNaN(year)==true){   
		return   false;   
	}
	if(isNaN(month)==true){   
		return   false;   
	}   
	if(isNaN(day)==true){   
		return   false;   
	}   
	if(month<1||month>12)   {     
		return   false;     
	}     
	if(day<1||day>31){     		
		return   false;     
	}
	if(month==2){       
		if(isLeapYear(year)&&day>29){     
			return   false;     
		}                 
		if(!isLeapYear(year)&&day>28){     
			return   false;     
		}     
	}     


	if((month==4||month==6||month==9||month==11)&&(day>30)){     
		return   false;     
	}     
	return   true;   
}
function getdate(str) {
	if(!isDate(str)) return null;
	var   datetime;   
	var   year,month,day;    
	datetime = trim(str);
	year = datetime.substring(0,4);   
	month=datetime.substring(5,7);   
	day=datetime.substring(8,10);   
	var ret = year + "-" + month + "-" + day;
	return ret;
}