function checkMail(emailStr,language) {
	if (!language) language = 0; //default deutsch
	var ue = String.fromCharCode(252); //umlaut
	
	var emailPat=/^(.+)@(.+)$/;
	var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]";
	var validChars="\[^\\s" + specialChars + "\]";
	var quotedUser="(\"[^\"]*\")";
	/* The following pattern applies for domains that are IP addresses,
	   rather than symbolic names.  E.g. joe@[123.124.233.4] is a legal
	   e-mail address. NOTE: The square brackets are required. */
	var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
	/* The following string represents an atom (basically a series of
	   non-special characters.) */
	var atom=validChars + '+';
	/* The following string represents one word in the typical username.
	   For example, in john.doe@somewhere.com, john and doe are words.
	   Basically, a word is either an atom or quoted string. */
	var word="(" + atom + "|" + quotedUser + ")";
	// The following pattern describes the structure of the user
	var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
	/* The following pattern describes the structure of a normal symbolic
	   domain, as opposed to ipDomainPat, shown above. */
	var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");


	/* Finally, let's start trying to figure out if the supplied address is
	   valid. */

	/* Begin with the coarse pattern to simply break up user@domain into
	   different pieces that are easy to analyze. */
	var matchArray=emailStr.match(emailPat);
	if (matchArray==null) {
	  /* Too many/few @'s or something; basically, this address doesn't
	     even fit the general mould of a valid e-mail address. */
		if (language == 0) alert("Die email-Adresse ist nicht korrekt (achten Sie auf @ und Punkte.)"); else alert("Email address seems incorrect (check @ and .'s)");
		return false;
	}
	var user=matchArray[1];
	var domain=matchArray[2];

		// See if "user" is valid 
	if (user.match(userPat)==null) {
    	// user is not valid
    	if (language == 0) alert("Der email-Username ist nicht korrekt."); else alert("The email username doesn't seem to be valid.");
    	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) {
		        if (language == 0) alert("Die Ziel-IP der email-Adresse ist ung" + ue + "ltig!"); else alert("Destination IP of email address is invalid!");
			return false;
		    }
	    }
	    return true;
	}
	
	// Domain is symbolic name
	var domainArray=domain.match(domainPat);
	if (domainArray==null) {
		if (language == 0) alert("Die email-Domain scheint ung" + ue + "ltig zu sein."); else alert("The email domain name doesn't seem to be valid.");
	    return false;
	}
	
	/* domain name seems valid, but now make sure that it ends in a
	   three-letter word (like com, edu, gov) or a two-letter word,
	   representing country (uk, nl), and that there's a hostname preceding 
	   the domain or country. */
	
	/* Now we need to break up the domain to get a count of how many atoms
	   it consists of. */
	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>4) {
	   // the address must end in a two letter or three letter word.
	   if (language == 0) alert("Die email-Domain scheint ung" + ue + "ltig zu sein."); else alert("The email address must end in a three or four-letter domain, or two letter country.")
	   return false;
	}

	// Make sure there's a host name preceding the domain.
	if (len<2) {
	   var errStr = "";
	   if (language == 0) errStr = "Der Hostname der email-Adresse fehlt!"; else errStr = "This email address is missing a hostname!"; 
	   alert(errStr)
	   return false;
	}
	
	// If we've gotten this far, everything's valid!
	return true;
}