function rusInducing num words out if strlen num if substr num switch

function rusInducing($num, $words)
{
	$out = "";
	if (strlen($num)>1) 
	{
		if (substr($num, 0, 1)!='1') 
		{
			switch(substr($num, 1, 1))
			{
				case 1:
					$out = $words[0]; 
					break;
				case 2:
				case 3:
				case 4:
					$out = $words[1]; 
					break;
				case 5:
				case 6:
				case 7:
				case 8:
				case 9:
				case 0:
					$out = $words[2];  
					break;
			}
		}
		else 
		{
			$out = $words[2];
		}		
	}
	else 
	{
		switch ($num)
		{
			case 1:
				$out = $words[0];
				break;
			case 2:
			case 3:
			case 4:
				$out = $words[1];
				break;
			case 5:
			case 7:
			case 8:
			case 9:
			case 0:
				$out = $words[2];
				break;
		}
	}
	return $out;
}