dir

<element dir="yonu" > ... </element>

<script type="text/javascript">

element.dir = yonu;

yonu = element.dir

</script>

<p id="yazi" dir="rtl">Lorem ipsum dolor sit amet ne demek? Lorem <br/>
ipsum dolor sit amet ne demek? Lorem ipsum dolor sit amet ne demek? Lorem <br/>
ipsum dolor sit amet ne demek? Lorem ipsum dolor sit amet ne demek? Son </p>

<input type="button" value="Soldan Sağa" onClick="SoldanSaga()" />
<input type="button" value="Sağdan Sola" onClick="SagdanSola()" />

<script type="text/javascript">

function SagdanSola(){
	document.getElementById('yazi').dir = 'rtl';
}
function SoldanSaga(){
	document.getElementById('yazi').dir = 'ltr';
}
</script>