PHP: Nucleotide Fun

Note: This is the PHP file that will run with the HTML file also titled Nucleotide Fun.

<?php

	$DNA = " does not contain U.";
	$RNA = " contains U.";
	$seq = $_GET['seq'];
	
	for($i=0; $i<strlen($seq); $i++)
	{
		if($seq[$i] == 'U' || $seq[$i] == 'u')
		{
			echo "The input sequence is  RNA because RNA" . $RNA . "\n";
			break;
		}
		
		else if($i == strlen($seq)-1)
		{
			echo "The input sequence is DNA because DNA" . $DNA . "\n";
		}
		
	}

?>