Stefan

<script>
	var text = "Test here";
	var rotText = "";
	const newLine = '<br>';
	
	rotText = rot13(text);
	document.write("Org:" + text + newLine);
	document.write("Enc:" + rotText + newLine);
	document.write("Dec:" + rot13(rotText) + newLine);
	
	function rot13(text){
		var rotString = "";
		
		for(var i=0; i< text.length; i++){
			var charCode = text.charCodeAt(i);
			console.log(charCode);
			
			if(charCode >= 97 && charCode <= 109){
				charCode +=13;
			}else if(charCode>=110 && charCode<=122){
				charCode -=13;
			
			}
			
			var letter = String.fromCharCode(charCode);
			rotString = rotString + letter;
			
		}
		
		return rotString;
	}
	
</script>