function emailCheck(emailStr) 
			{
				var checkTLD=1;
				var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;
				var emailPat=/^(.+)@(.+)$/;
				var specialChars="\\(\\)><@,;:\\\\\\\"\\.\\[\\]";
				var validChars="\[^\\s" + specialChars + "\]";
				var quotedUser="(\"[^\"]*\")";
				var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
				var atom=validChars + '+';
				var word="(" + atom + "|" + quotedUser + ")";
				var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
				var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");
				var matchArray=emailStr.match(emailPat);
				
				if (matchArray==null) 
				{
					alert("Email address seems incorrect (check @ and .'s)");
					return false;
				}
				var user=matchArray[1];
				var domain=matchArray[2];
				
				for (i=0; i<user.length; i++)
				{
					if (user.charCodeAt(i)>127) 
					{
						alert("Ths username contains invalid characters.");
						return false;
					}
				}
				for (i=0; i<domain.length; i++) 
				{
					if (domain.charCodeAt(i)>127) 
					{
						alert("Ths domain name contains invalid characters.");
						return false;
					}
				}
			
				if (user.match(userPat)==null)
				{
					alert("The username doesn't seem to be valid.");
					return false;
				}
			
				var IPArray=domain.match(ipDomainPat);
			
				if (IPArray!=null) 
				{
					for (var i=1;i<=4;i++)
					{
						if (IPArray[i]>255)
						{
							alert("Destination IP address is invalid!");
							return false;
						}
					}
					return true;
				}
			
				var atomPat=new RegExp("^" + atom + "$");
				var domArr=domain.split(".");
				var len=domArr.length;
				for (i=0;i<len;i++) 
				{
					if (domArr[i].search(atomPat)==-1)
					{
						alert("The domain name does not seem to be valid.");
						return false;
					}
				}
			
				if (checkTLD && domArr[domArr.length-1].length!=2 && domArr[domArr.length-1].search(knownDomsPat)==-1) 
				{
					alert("The address must end in a well-known domain or two letter " + "country.");
					return false;
				}
				if (len<2) 
				{
					alert("This address is missing a hostname!");
					return false;
				}
				return true;
			}