diff --git a/config/categories.php b/config/categories.php
index 6f3f6818..2ab9d69a 100644
--- a/config/categories.php
+++ b/config/categories.php
@@ -30,7 +30,8 @@
 
  if($_POST['action']=="edit")
  {
- 	if($_POST['id'] && $_POST['category'] && $_POST['mingrade'] && $_POST['maxgrade'])
+ 	//ues isset($_POST['mingrade']) instead of just $_POST['mingrade'] to allow entering 0 for kindergarden
+ 	if($_POST['id'] && $_POST['category'] && isset($_POST['mingrade']) && $_POST['maxgrade'])
 	{
 		$q=mysql_query("SELECT id FROM projectcategories WHERE id='".$_POST['id']."' AND year='".$config['FAIRYEAR']."'");
 		echo mysql_error();
@@ -57,7 +58,8 @@
 
  if($_POST['action']=="new")
  {
- 	if($_POST['id'] && $_POST['category'] && $_POST['mingrade'] && $_POST['maxgrade'])
+ 	//ues isset($_POST['mingrade']) instead of just $_POST['mingrade'] to allow entering 0 for kindergarden
+ 	if($_POST['id'] && $_POST['category'] && isset($_POST['mingrade']) && $_POST['maxgrade'])
 	{
 		$q=mysql_query("SELECT id FROM projectcategories WHERE id='".$_POST['id']."' AND year='".$config['FAIRYEAR']."'");
 		if(mysql_num_rows($q))
@@ -130,11 +132,11 @@
 	 while($r=mysql_fetch_object($q))
 	 {
 		echo "<tr>";
-		echo " <td>$r->id</td>";
+		echo " <td align=\"center\">$r->id</td>";
 		echo " <td>".i18n($r->category)."</td>";
-		echo " <td>$r->mingrade</td>";
-		echo " <td>$r->maxgrade</td>";
-		echo " <td>";
+		echo " <td align=\"center\">$r->mingrade</td>";
+		echo " <td align=\"center\">$r->maxgrade</td>";
+		echo " <td align=\"center\">";
 				echo "<a title=\"Edit\" href=\"".$_SERVER['PHP_SELF']."?action=edit&amp;edit=$r->id\"><img src=\"".$config['SFIABDIRECTORY']."/images/16/edit.".$config['icon_extension']."\" border=0></a>";
 				echo "&nbsp; &nbsp;";
 				echo "<a title=\"Remove\" onClick=\"return confirmClick('Are you sure you want to remove this age category?');\" href=\"".$_SERVER['PHP_SELF']."?action=remove&amp;remove=$r->id\"><img src=\"".$config['SFIABDIRECTORY']."/images/16/button_cancel.".$config['icon_extension']."\" border=0></a>";