diff --git a/src/mibew/libs/common/forms.php b/src/mibew/libs/common/forms.php
index 616245aa..ebe66f61 100644
--- a/src/mibew/libs/common/forms.php
+++ b/src/mibew/libs/common/forms.php
@@ -44,11 +44,20 @@ function form_value_cb($page, $name) {
 	return false;
 }
 
-function form_value_mb($key, $id)
-{
-	global $page;
-	if (isset($page) && isset($page["form$key"]) && is_array($page["form$key"])) {
-		return in_array($id, $page["form$key"]);
+
+/**
+ * Checks if form variable is array and has element with specified key.
+ *
+ * @param array $page The page array. All form variables are prefixed with
+ * "form" string.
+ * @param string $name Form variable name.
+ * @param string $key Key of the element to check.
+ * @return boolean Returns TRUE only if specified form variable is set, is an
+ * array has element with the specified key. In all other cases returns FALSE.
+ */
+function form_value_mb($page, $name, $key) {
+	if (!empty($page) && isset($page["form$name"]) && is_array($page["form$name"])) {
+		return in_array($key, $page["form$name"]);
 	}
 	return false;
 }
diff --git a/src/mibew/styles/pages/default/views/groupmembers.php b/src/mibew/styles/pages/default/views/groupmembers.php
index 734401a1..1391f952 100644
--- a/src/mibew/styles/pages/default/views/groupmembers.php
+++ b/src/mibew/styles/pages/default/views/groupmembers.php
@@ -44,7 +44,7 @@ require_once(dirname(__FILE__).'/inc_errors.php');
 <?php foreach( $page['operators'] as $pm ) { ?>
 	<div class="field">
 		<div class="fvaluenodesc">
-			<input id="op<?php echo htmlspecialchars($pm['operatorid']); ?>" type="checkbox" name="op<?php echo htmlspecialchars($pm['operatorid']); ?>" value="on"<?php echo form_value_mb('op',$pm['operatorid']) ? " checked=\"checked\"" : "" ?>/> 
+			<input id="op<?php echo htmlspecialchars($pm['operatorid']); ?>" type="checkbox" name="op<?php echo htmlspecialchars($pm['operatorid']); ?>" value="on"<?php echo form_value_mb($page, 'op',$pm['operatorid']) ? " checked=\"checked\"" : "" ?>/> 
 			<label for="op<?php echo htmlspecialchars($pm['operatorid']); ?>"><?php echo htmlspecialchars(topage($pm['vclocalename'])) ?> (<a href="operator.php?op=<?php echo $pm['operatorid'] ?>"><?php echo htmlspecialchars(topage($pm['vclogin'])) ?></a>)</label>
 		</div>
 	</div>
diff --git a/src/mibew/styles/pages/default/views/operator_groups.php b/src/mibew/styles/pages/default/views/operator_groups.php
index 6459b9a4..e2831a68 100644
--- a/src/mibew/styles/pages/default/views/operator_groups.php
+++ b/src/mibew/styles/pages/default/views/operator_groups.php
@@ -45,7 +45,7 @@ require_once(dirname(__FILE__).'/inc_errors.php');
 	<div class="field level<?php echo $pm['level'] ?>">
 		<label for="group<?php echo htmlspecialchars($pm['groupid']); ?>" class="flabel"><?php echo htmlspecialchars(topage($pm['vclocalname'])) ?></label>
 		<div class="fvalue">
-			<input id="group<?php echo htmlspecialchars($pm['groupid']); ?>" type="checkbox" name="group<?php echo htmlspecialchars($pm['groupid']); ?>" value="on"<?php echo form_value_mb('group',$pm['groupid']) ? " checked=\"checked\"" : "" ?><?php echo $page['canmodify'] ? "" : " disabled=\"disabled\"" ?>/>
+			<input id="group<?php echo htmlspecialchars($pm['groupid']); ?>" type="checkbox" name="group<?php echo htmlspecialchars($pm['groupid']); ?>" value="on"<?php echo form_value_mb($page, 'group',$pm['groupid']) ? " checked=\"checked\"" : "" ?><?php echo $page['canmodify'] ? "" : " disabled=\"disabled\"" ?>/>
 		</div>
 		<label for="group<?php echo htmlspecialchars($pm['groupid']); ?>" class="fdescr"> &mdash; <?php echo $pm['vclocaldescription'] ? htmlspecialchars(topage($pm['vclocaldescription'])) : getlocal("operator.group.no_description") ?></label>
 		<br clear="all"/>
diff --git a/src/mibew/styles/pages/default/views/permissions.php b/src/mibew/styles/pages/default/views/permissions.php
index 93082696..3194349f 100644
--- a/src/mibew/styles/pages/default/views/permissions.php
+++ b/src/mibew/styles/pages/default/views/permissions.php
@@ -43,7 +43,7 @@ require_once(dirname(__FILE__).'/inc_errors.php');
 	</p>
 <?php foreach( $page['permissionsList'] as $pm ) { ?>
 	<label>
-		<input type="checkbox" name="permissions<?php echo $pm['id'] ?>" value="on"<?php echo form_value_mb('permissions',$pm['id']) ? " checked=\"checked\"" : "" ?><?php echo $page['canmodify'] ? "" : " disabled=\"disabled\"" ?>/> <?php echo $pm['descr'] ?>
+		<input type="checkbox" name="permissions<?php echo $pm['id'] ?>" value="on"<?php echo form_value_mb($page, 'permissions',$pm['id']) ? " checked=\"checked\"" : "" ?><?php echo $page['canmodify'] ? "" : " disabled=\"disabled\"" ?>/> <?php echo $pm['descr'] ?>
 	</label>
 	<br/>
 <?php } ?>