function isNumberKey(evt)
{
 var charCode = (evt.which) ? evt.which : event.keyCode
 if (charCode > 31 && (charCode < 48 || charCode > 57))
	return false;
	
 return true;
}

function checkEmailFormat(email) {
	invalidChars = " ~\'^\`\"*+=\\|][(){}$&!#%/:,;";
	// Check for invalid characters as defined above
	for (i=0; i<invalidChars.length; i++) {
		badChar = invalidChars.charAt(i);
		if (email.indexOf(badChar,0) > -1) {
			return false;
		}
	}
	
	lengthOfEmail = email.length;
	if ((email.charAt(lengthOfEmail - 1) == ".") || (email.charAt(lengthOfEmail - 2) == ".")) {
		return false;
	}
	
	Pos = email.indexOf("@",1);
	if (email.charAt(Pos + 1) == ".") {
		return false;
	}
	
	while ((Pos < lengthOfEmail) && ( Pos != -1)) {
		Pos = email.indexOf(".",Pos);
		if (email.charAt(Pos + 1) == ".") {
			return false;
		}
		if (Pos != -1) {
			Pos++;
		}
	}
	
	// There must be at least one @ symbol
	atPos = email.indexOf("@",1);
	if (atPos == -1) {
		return false;
	}
	// But only ONE @ symbol
	if (email.indexOf("@",atPos+1) != -1) {
		return false;
	}
	// Also check for at least one period after the @ symbol
	periodPos = email.indexOf(".",atPos);
	if (periodPos == -1) {
		return false;
	}
	if (periodPos+3 > email.length) {
		return false;
	}
	return true;
}