function emailCheck (emailStr)
	{	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]
		
		if (user.match(userPat)==null)
			{	alert("The email address' 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("The email address' destination IP address is invalid!")
								return false
							}
					}
				return true
			}	
					
		var domainArray=domain.match(domainPat)
		
		if (domainArray==null) 
			{	alert("The email address' domain name doesn't seem to be valid.")
				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)
			{	alert("The email address must end in a three-letter domain, or two letter country.")
				return false
			}
		
		if (len<2)
			{	var errStr="The email address is missing a hostname!"
				alert(errStr)
				return false
			}
			
		return true;
	}