function isAlpha (text)
{
	var lowerChars = "abcdefghijklmnopqrstuvwxyz";
	var upperChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	var validValues = lowerChars + upperChars;
	
	for (i = 0; i < text.length; i++)
	{
		char = text.charAt(i);
		if (validValues.indexOf(char) < 0)
		{
			return false;
		}
	}
	return true;
}