PHP browse script: get unique results

programming
1 

<p>Browse by:
<ul>
<li><a href="clients.php?browse=city">City</a></li>
	<?php
	if(isset($_GET['browse'])||$_GET['browse']=='city')
	{
		echo '<ul>';
		$query_browse = 'SELECT * FROM clients';
		$result_browse = mysql_query($query_browse);
		while($row_browse=mysql_fetch_array($result_browse))
		{
			echo '<li>'.$row_browse['city'].'</li>';
		}
		echo '</ul>';
	}
	?>

<li><a href="clients.php?browse=state">State</a></li>
<li><a href="clients.php?browse=zipcode">Zipcode</a></li>
<li><a href="clients.php?browse=country">Country</a></li>
</ul>
</p>

Im trying to work on a Browse Script. If there are 10 records that contain TEXAS as state, it prints 10 TEXAS results. But I just want to print ONE TEXAS result.

How can I only print ONE result of each?