function checkEmail(f,fld) {

    var s = f.elements[fld].value;
    if (s) {
	var atsymbol = "@";
	var atoffset = s.indexOf(atsymbol);
	if (atoffset == -1) {
	    alert("Address not valid. '@' is missing.");
	    return false
	} else {
	    if (atoffset > s.lastIndexOf(".") || atoffset < s.lastIndexOf(atsymbol)) {
	        alert("Address not valid. No domain name or there are more than one '@'.");
	        return false
	    } else {
			var re = /[^A-Za-z0-9_@\.\-]/;
			var foundArray = re.exec(s);
			if (foundArray) {
			    if (foundArray == " ") {
				alert("A space cannot be used in an e-mail address")
			    } else {
				alert("" + foundArray + " cannot be used in an e-mail address")
			    }
			    return(false)
			} else {
			    return(true)
			}
	    }
	}	
    } else {
	alert('Please enter "Email address"');
	return(false)
    }
}