Something

			if ($page == 3) {
				echo "<center><form action=send_message.php method=post>";
				echo "<table width=75% height=300>";
				echo "<tr>";
				echo "<td>To:</td>";
				echo "<td height=10>";
				echo "<select name=user>";
				$result=mysql_query("SELECT * FROM users ORDER BY id ;");
					while( $row=mysql_fetch_array($result) )
					{
					echo "<option> ".$row['username']."</option>";
					}
				echo "</select>";
				echo "</td>";
				echo "</tr>";
				echo "<tr>";
				echo "<td>";
				echo "Body:";
				echo "</td>";
				echo "<td>";
				echo "<textarea style='width:100%; height:100%;' name=message></textarea>";
				echo "</td>";
				echo "</tr>";
				echo "<tr>";
				echo "<td colspan=2 height=10>";
				echo "<input type=hidden name=who value='cat' />";
				echo "<center><input type=submit value=send /></form></center>";
				echo "</td>";
				echo "</tr>";
				echo "</table></center>";
			}