function CheckEmail (obj, lgFlag) 
{

	if (typeof obj == "undefined") {
		return true;
	}
	
	var emailStr = obj.value;
	
	if (emailStr != "" ){
	
		var emailPat=/^(.+)@(.+)$/
		var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"
		var validChars="\[^\\s" + specialChars + "\]"
		var firstChars=validChars
		var quotedUser="(\"[^\"]*\")"
		var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/
		var atom="(" + firstChars + validChars + "*" + ")"
		var word="(" + atom + "|" + quotedUser + ")"
		var userPat=new RegExp("^" + word + "(\\." + word + ")*$")
		var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")
		var matchArray=emailStr.match(emailPat)
		
		var alertStr = (!lgFlag || lgFlag == "0")?"E-mail有错误，请你再次输入。":"Wrong E-mail format";
		
		if (matchArray==null) {
			alert(alertStr);
			obj.focus();
			return false;
		}

		var user=matchArray[1]
		var domain=matchArray[2]

		if (user.match(userPat)==null) {
		    // user is not valid
		     alert(alertStr);
		    obj.focus();
			return false;
		}

		var IPArray=domain.match(ipDomainPat)
		if (IPArray!=null) {
		    // this is an IP address
			  for (var i=1;i<=4;i++) {
			    if (IPArray[i]>255) {
			        alert(alertStr);
					obj.focus();
					return false;
			    }
		    }
		}

		var domainArray=domain.match(domainPat)
		if (domainArray==null) {
			alert(alertStr);
		    obj.focus();
			return false;
		}

		var atomPat=new RegExp(atom,"g")
		var domArr=domain.match(atomPat)
		var len=domArr.length
		if (domArr[domArr.length-1].length<2 || 
		    domArr[domArr.length-1].length>3) {
		   // the address must end in a two letter or three letter word.
		   alert(alertStr);
		   obj.focus();
		   return false;
		}

		if (domArr[domArr.length-1].length==2 && len<3) {
		   var errStr="E-mail有错误，请你再次输入。"
	   	   errStr+=" 메일주소 뒷부분의 국가코드는 반드시 "
  	 	   errStr+=" 다음과 같은 형식으로 되어야 합니다.(ex: com, co, pub, pu, etc.)"
		   alert(errStr);
		   obj.focus();
		   return false;
		}


		if (domArr[domArr.length-1].length==3 && len<2) {
		   var errStr="This address is missing a hostname!" 
		   alert(errStr);
		   obj.focus();
		   return false;
		}
	}
	
	return true;
}