Signed-off-by: Leo-Andres Hofmann <hofmann(a)leo-andres.de>
---
 html/cgi-bin/zoneconf.cgi     |  6 +++---
 html/html/include/zoneconf.js | 27 +++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/html/cgi-bin/zoneconf.cgi b/html/cgi-bin/zoneconf.cgi
index 1d30450ed..eb6cd0e66 100644
--- a/html/cgi-bin/zoneconf.cgi
+++ b/html/cgi-bin/zoneconf.cgi
@@ -410,7 +410,7 @@ foreach (@zones) {
 
 	print <<END
 		<td class='heading bold $_'>$uc<br>
-			<select name="MODE $uc">
+			<select name="MODE $uc" data-zone="$uc" onchange="changeZoneMode(this)">
 				<option value="DEFAULT" $mode_selected{"DEFAULT"}>$Lang::tr{"zoneconf nicmode default"}</option>
 				<option value="BRIDGE" $mode_selected{"BRIDGE"}>$Lang::tr{"zoneconf nicmode bridge"}</option>
 				<option value="MACVTAP" $mode_selected{"MACVTAP"}>$Lang::tr{"zoneconf nicmode macvtap"}</option>
@@ -544,7 +544,7 @@ foreach (@zones) { # load settings and prepare form elements for each zone
 	# enable checkbox HTML
 	my $row_1 = <<END
 		<td>
-			<input type="checkbox" name="STP-$uc" $disabled $checked>
+			<input type="checkbox" id="STP-$uc" name="STP-$uc" data-zone="$uc" onchange="changeEnableSTP(this)" $disabled $checked>
 		</td>
 END
 ;
@@ -553,7 +553,7 @@ END
 	# priority input box HTML
 	my $row_2 = <<END
 		<td>
-			<input type="number" class="stp-priority" name="STP-PRIORITY-$uc" min="1" max="65535" value="$stp_priority" $disabled>
+			<input type="number" class="stp-priority" id="STP-PRIORITY-$uc" name="STP-PRIORITY-$uc" min="1" max="65535" value="$stp_priority" $disabled>
 		</td>
 END
 ;
diff --git a/html/html/include/zoneconf.js b/html/html/include/zoneconf.js
index d76f0ab68..d27a79bc8 100644
--- a/html/html/include/zoneconf.js
+++ b/html/html/include/zoneconf.js
@@ -54,3 +54,30 @@ function highlightAccess(selectObj) {
 	//if interface is assigned, highlight table cell in zone color
 	colorParentCell(selectObj, zoneColor, (selectObj.value !== 'NONE'));
 }
+
+//update zone mode
+function changeZoneMode(selectObj) {
+	if(!(selectObj && ('zone' in selectObj.dataset))) {
+		return; //required parameters are missing
+	}
+
+	// STP enable checkbox
+	let stpEnable = document.getElementById('STP-' + selectObj.dataset.zone);
+	if(stpEnable) {
+		stpEnable.disabled = (selectObj.value !== 'BRIDGE'); //STP is available if zone is in bridge mode
+		stpEnable.checked = stpEnable.checked && (! stpEnable.disabled); //un-check if disabled
+		stpEnable.dispatchEvent(new Event('change'));
+	}
+}
+
+//STP enable checkbox change toggles priority input
+function changeEnableSTP(inputObj) {
+	if(!(inputObj && ('zone' in inputObj.dataset))) {
+		return; //required parameters are missing
+	}
+
+	let priority = document.getElementById('STP-PRIORITY-' + inputObj.dataset.zone);
+	if(priority) {
+		priority.disabled = inputObj.disabled || (! inputObj.checked);
+	}
+}
-- 
2.27.0.windows.1