จนปัญญาแล้วครับ ช่วยทีนะครับเรื่องการดึงข้อมูลมาโชว์ใน text field

<?
$class=$_GET['class'];
//เอาclassมาหาชื่อครูประจำชั้น

   $result=mysql_connect($dbhost,$dbuser,$dbpassword) or die("Unable to connect to database");
    strsql ="Select  * from  test where clas='$class'";
    $result = mysql_query($strsql);
    $row = mysql_fetch_array($result);
    $teacher=$row['teacher'];


?>
<form name="frm1" action="classroom.php" method="get">		
		<select name="class" size="1" onchange="location=this.options[this.selectedIndex].value;">
  			<option value='http://localhost/classroom.php?class=p1'>ป.1</option>
  			<option value='http://localhost/classroom.php?class=p2'>ป.2</option>
  			<option value='http://localhost/classroom.php?class=p3'>ป.3</option>
  			<option value='http://localhost/classroom.php?class=p4'>ป.4</option>
  			<option value='http://localhost/classroom.php?class=p5'>ป.5</option>
  			<option value='http://localhost/classroom.php?class=p6'>ป.6</option>
			<option selected value="http://localhost/classroom.php?class=<? echo $class ?>"><? echo $class ?></option>				
		</select>

</form>
<input name="teacher" type="text"  value="<? echo $teacher ?>"/>

		<select name="class" size="1" onchange="location=this.options[this.selectedIndex].value;">
  			<option value='http://www.namebom.com/classroom.php?class=p1'>ป.1</option>
  			<option value='http://www.namebom.com/classroom.php?class=p2'>ป.2</option>
  			<option value='http://www.namebom.com/classroom.php?class=p3'>ป.3</option>
  			<option value='http://www.namebom.com/classroom.php?class=p4'>ป.4</option>
  			<option value='http://www.namebom.com/classroom.php?class=p5'>ป.5</option>
  			<option value='http://www.namebom.com/classroom.php?class=p6'>ป.6</option>
			<option selected value="http://www.namebom.com/classroom.php?class=<? echo $class ?>"><? echo $class ?></option>				
		</select>