diff --git a/usr/local/www/firewall_nat_edit.php b/usr/local/www/firewall_nat_edit.php
index a9399f8114..42da1ba0ff 100755
--- a/usr/local/www/firewall_nat_edit.php
+++ b/usr/local/www/firewall_nat_edit.php
@@ -718,7 +718,7 @@ include("fbegin.inc"); ?>
 					<tr>
 						<td><?=gettext("from:"); ?>&nbsp;&nbsp;</td>
 						<td>
-							<select name="dstbeginport" class="formselect" onchange="dst_rep_change();ext_change()">
+							<select name="dstbeginport" id="dstbeginport" class="formselect" onchange="dst_rep_change();ext_change()">
 								<option value="">(<?=gettext("other"); ?>)</option>
 <?php 							$bfound = 0;
 								foreach ($wkports as $wkport => $wkportdesc): ?>
@@ -731,7 +731,7 @@ include("fbegin.inc"); ?>
 					<tr>
 						<td><?=gettext("to:"); ?></td>
 						<td>
-							<select name="dstendport" class="formselect" onchange="ext_change()">
+							<select name="dstendport" id="dstendport" class="formselect" onchange="ext_change()">
 								<option value="">(<?=gettext("other"); ?>)</option>
 <?php							$bfound = 0;
 								foreach ($wkports as $wkport => $wkportdesc): ?>
@@ -761,7 +761,7 @@ include("fbegin.inc"); ?>
                 <tr name="lprtr" id="lprtr">
                   <td width="22%" valign="top" class="vncellreq"><?=gettext("Redirect target port"); ?></td>
                   <td width="78%" class="vtable">
-                    <select name="localbeginport" class="formselect" onchange="ext_change();check_for_aliases();">
+                    <select name="localbeginport" id="localbeginport" class="formselect" onchange="ext_change();check_for_aliases();">
                       <option value="">(<?=gettext("other"); ?>)</option>
                       <?php $bfound = 0; foreach ($wkports as $wkport => $wkportdesc): ?>
                       <option value="<?=$wkport;?>" <?php if ($wkport == $pconfig['localbeginport']) {
diff --git a/usr/local/www/javascript/firewall_nat_edit/firewall_nat_edit.js b/usr/local/www/javascript/firewall_nat_edit/firewall_nat_edit.js
index bd88145e8b..501481db5f 100644
--- a/usr/local/www/javascript/firewall_nat_edit/firewall_nat_edit.js
+++ b/usr/local/www/javascript/firewall_nat_edit/firewall_nat_edit.js
@@ -138,6 +138,12 @@ function proto_change() {
 		document.getElementById("sprtable").style.display = 'none';
 		document.getElementById("dprtr").style.display = 'none';
 		document.getElementById("lprtr").style.display = 'none';
+		document.getElementById("dstbeginport").selectedIndex = 0;
+		document.getElementById("dstbeginport_cust").value = "";
+		document.getElementById("dstendport").selectedIndex = 0;
+		document.getElementById("dstendport_cust").value = "";
+		document.getElementById("localbeginport").selectedIndex = 0;
+		document.getElementById("localbeginport_cust").value = "";
 	}
 }