//检查身份证格式
String.prototype.isIDCard = function()
{
    var vCid = this.trim();
    var vSum = 0;
    var vReg = /^([\d]{17}[xX\d]|[\d]{15})$/;
    var vCity = '|11|12|13|14|15|21|22|23|31|32|33|34|35|36|37|41|42|43|44|45|46|50|51|52|53|54|61|62|63|64|65|71|81|82|91|';
    
    if (!vReg.test(vCid)) 
		return false;
    if(vCity.indexOf(parseInt(vCid.substr(0,2))) == '-1') 
		return false;
    
    vCid = vCid.replace(/[xX]$/i, 'a');
    if (vCid.length == 18)
    {
        vBirthday = vCid.substr(6, 4) + '/' + Number(vCid.substr(10, 2)) + '/' + Number(vCid.substr(12, 2));
    } else {
        vBirthday = '19' + vCid.substr(6, 2) + '/' + Number(vCid.substr(8, 2)) + '/' + Number(vCid.substr(10, 2));
    }
    
    var vDate = new Date(vBirthday);
    if (vBirthday != (vDate.getFullYear() + '/' + (vDate.getMonth() + 1) + '/' + vDate.getDate())) 
		return false;
    
    if (vCid.length == 18)
    {
        for(var i = 17 ; i >= 0 ; i--) 
			vSum += (Math.pow(2, i) % 11) * parseInt(vCid.charAt(17 - i), 11);
        if(vSum % 11 != 1) 
			return false;
    }
    return true;
}

//检查电子邮箱格式
String.prototype.isMail = function()
{
	var mail = this.trim();
	var reg = /^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+((\.[a-zA-Z0-9_-]{2,3}){1,2})$/;
    return reg.test(mail);
}

//检查是否是数字
String.prototype.isNumber = function()
{
	var oNum = this.trim();
	var strP = /^\d+(\.\d+)?$/;
	if(!strP.test(oNum))
		return false;
	try{
		if(parseFloat(oNum)!=oNum) 
			return false;
	}
	catch(ex)
	{
		return false;
	}
	return true;
}

//检查电话号码(可带区号或不带区号，区号用-分隔)
String.prototype.isPhone = function()
{
	var phoneNumber = this.trim();
	var reg = /^((0\d{2,3})-)?(\d{7,8})(-(\d{3,}))?$/;
	return reg.test(phoneNumber);
}

//检查手机号码
String.prototype.isMobile = function()
{
	var mobile = this.trim();
	var reg = /^(?:13\d|15\d)\d{5}(\d{3}|\*{3})$/;
	return reg.test(mobile);
}

//检查IP地址
String.prototype.isIp = function()
{
	var strIp = this.trim();
    var IPReg = /^(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])$/;
    return IPReg.test(strIp);
}


//验证日期格式(2014-11-07)，暂不支持带时间的日期
String.prototype.isDate = function()
{
	var datestr = this.trim();
	var regex = /^(\d{4})-(\d{1,2})-(\d{1,2})$/; 
	if( regex.test(datestr) ){

		var noArr = datestr.split("-");
		var year = eval(noArr[0]);
		var month = eval(noArr[1]);
		var day = eval(noArr[2]);
		if ( year < 1 || month < 1 || month > 12 || day < 1 || day > 31) {
			return false;
		}
		if ((month == 4 || month == 6 || month == 9 || month == 11) && day > 30){
			return false;
		}
		if (month == 2){
			if ((year % 4 != 0) && day > 29) { 
				return false;
			}
			if (year % 4 == 0){
				if(year % 100 == 0 && year % 400 != 0 && day > 29){
					return false;
				}
				else if (day > 28){ 
					return false;
				}
			}
		}
		return true;
	}else{
	   return false;
	}
}

<script type="text/javascript">
var test_str = "2014-11-07";	//要验证的字符串
if(test_str.isDate()){
	alert("success");
}else{
	alert("fail");
}
</script>