Read function in php

<?php

mysql_connect("localhost","root","");

mysql_select_db("test1");

?>

<table width="400" border="1">

<tr>

<td>sl number</td>

<td>field_name </td>

<td>field_pass </td>

<td>field_address </td>

</tr>

<?php

$i=1;

$query="Select * from tablename ";

$RES=mysql_query($query);

while($ROW=mysql_fetch_array($RES))

{

?>

<tr>

<td><?php echo $i ?></td>

<td><?php echo $ROW[1]; ?></td>

<td><?php echo $ROW[2]; ?></td>

<td><?php echo $ROW[3]; ?></td>

</tr>

<?php

$i=$i+1;

}

?>

</table>