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){return false}
	var user=matchArray[1]
	var domain=matchArray[2]
	
	// See if "user" is valid 
	if (user.match(userPat)==null){return false}
	
	/* if the e-mail address is at an IP address (as opposed to a symbolic host name) make sure the IP address is valid. */
	var IPArray=domain.match(ipDomainPat)
	if (IPArray!=null) 
	{
	    // this is an IP address
		for (var i=1;i<=4;i++){if (IPArray[i]>255) {return false}}
		return true
	}
	
	// Domain is symbolic name
	var domainArray=domain.match(domainPat)
	if (domainArray==null){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) {return false}
	
	// Make sure there's a host name preceding the domain.
	if (len<2) {var errStr="This address is missing a hostname!"; return false;}
	
	// If we've gotten this far, everything's valid!
	return true;		
}