1st thing: You don't have to create array for your radio buttons. Use like:
<input type="checkbox" value="Siomay" name="tile[]">Siomay <br>
<input type="radio" name="field1" value="4" />Small
<input type="radio" name="field1" value="5" />Large<br>
2nd thing: change :
$Tile = mysql_real_escape_string($_POST['tile']);
$Field = mysql_real_escape_string($_POST['field1']);
to
$Tile = mysql_real_escape_string($_POST['tile'])!=""?mysql_real_escape_string($_POST['tile']):0;
$Field = mysql_real_escape_string($_POST['field1'])!=''?mysql_real_escape_string($_POST['field1']):0;