protected function numToLetter($num, $uppercase = FALSE)
	{
		$num -= 1;

		$letter = 	chr(($num % 26) + 97);
		$letter .= 	(floor($num/26) > 0) ? str_repeat($letter, floor($num/26)) : '';
		return 		($uppercase ? strtoupper($letter) : $letter);
	}
protected function numToLetter($num, $uppercase = FALSE)
	{
		$num -= 1;

		$letter = 	chr(($num % 26) + 97);
		$letter .= 	(floor($num/26) > 0) ? str_repeat($letter, floor($num/26)) : '';
		return 		($uppercase ? strtoupper($letter) : $letter);
	}
protected function numToLetter ( $ num , $ uppercase = FALSE ) { $ num -= 1 ; $ letter = chr ( ( $ num % 26 ) + 97 ) ; $ letter .= ( floor ( $ num / 26 ) > 0 ) ? str_repeat ( $ letter , floor ( $ num / 26 ) ) : '' ; return ( $ uppercase ? strtoupper ( $ letter ) : $ letter ) ; }
Takes a number and converts it to a-z,aa-zz,aaa-zzz, etc with uppercase option

@access	protected
@param	int	number to convert
@param	bool	upper case the letter on return?
@return	string	letters from number input
Takes a number and converts it to a - z aa - zz aaa - zzz etc with uppercase option