function ChkUtil() {
}   
// 
ChkUtil.onFocus = function (obj) {
	if (obj) {
		obj.focus();
	}
};   
//  
ChkUtil.trim = function (str) {
	var patrn = /(^\s+|\s$)/g;
	return str.replace(patrn, "");
};   
//  
ChkUtil.isNull = function (str) {
	if (null == str || "" == ChkUtil.trim(str)) {
		return true;
	} else {
		return false;
	}
};
ChkUtil.isAlpha = function (str) {
	var re = /[^a-zA-Z]/g;
	if (re.test(str)) {
		return false;
	}
	return true;
};
ChkUtil.isAlphaNumeric = function (str) {
	var re = /[^a-zA-Z0-9-]/g;
	if (re.test(str)) {
		return false;
	}
	return true;
};
ChkUtil.isAlphaNumericUnderlined = function (str) {
	var re = /^\w+$/;
	return re.test(str);
};
//   
ChkUtil.isDigit = function (digit) {
	var patrn = /^[0-9]{1,20}$/;
	return patrn.test(digit);
};
ChkUtil.isLength = function (str, len) {
	return str.length == len;
};
ChkUtil.isLengthBetween = function (str, min, max) {
	return (str.length >= min) && (str.length <= max);
};
ChkUtil.isString6_20 = function (str) {
	var patrn = /^(\w){6,20}$/;
	return patrn.test(str);
}; 
//  
ChkUtil.isString3_12 = function (str) {
	var patrn = /^(\w){3,12}$/;
	return patrn.test(str);
};   
//
ChkUtil.isMobile = function (mobile) {
	var patrn = /^[+]{0,1}(\d){1,3}[ ]?([-]?((\d)|[ ]){1,12})+$/;
	return patrn.test(mobile);
};   
// 
ChkUtil.isEmail = function (email) {
	var patrn = /^([a-zA-Z0-9._-])+@([a-zA-Z0-9_-])+(\.[a-zA-Z0-9_-])+/;
	return patrn.test(email);
};
ChkUtil.IsValidDate = function (str) {
	if (str === "") {
		return true;
	}
	var pattern = /^((\d{4})|(\d{2}))-(\d{1,2})-(\d{1,2})$/g;
	if (!pattern.test(str)) {
		return false;
	}
	var arrDate = str.split("-");
	if (parseInt(arrDate[0], 10) < 100) {
		arrDate[0] = 2000 + parseInt(arrDate[0], 10) + "";
	}
	var date = new Date(arrDate[0], (parseInt(arrDate[1], 10) - 1) + "", arrDate[2]);
	if (date.getFullYear() == arrDate[0] && date.getMonth() == (parseInt(arrDate[1], 10) - 1) + "" && date.getDate() == arrDate[2]) {
		return true;
	} else {
		return false;
	}
};
ChkUtil.radioIsCheck = function (radioName) {
	var obj = document.getElementsByName(radioName);
	for (i = 0; i < obj.length; i++) {
		if (obj[i].checked) {
			return true;
		}
	}
	return false;
};
ChkUtil.checkIsChinese = function (str) {
	if (str === "") {
		return true;
	}
	var len = str.length;
	for (var i = 0; i < len; i++) {
		if (str.charCodeAt(i) < 0 || str.charCodeAt(i) > 255) {
			return false;
		}
	}
	return true;
};