diff --git a/mix/ClientModel.cpp b/mix/ClientModel.cpp
index 450f28433..f12bcc1d8 100644
--- a/mix/ClientModel.cpp
+++ b/mix/ClientModel.cpp
@@ -355,9 +355,7 @@ void ClientModel::showDebuggerForTransaction(ExecutionResult const& _t)
 				//register new local variable initialization
 				auto localIter = contract->locals().find(LocationPair(instruction.getLocation().start, instruction.getLocation().end));
 				if (localIter != contract->locals().end())
-				{
 					solLocals[s.stack.size()] = new QVariableDeclaration(debugData, localIter.value().name.toStdString(), localIter.value().type);
-				}
 			}
 
 			if (instruction.type() == dev::eth::Tag)
diff --git a/mix/CodeModel.cpp b/mix/CodeModel.cpp
index 8af9e465c..f033c3405 100644
--- a/mix/CodeModel.cpp
+++ b/mix/CodeModel.cpp
@@ -371,7 +371,6 @@ SolidityType CodeModel::nodeType(solidity::Type const* _type)
 	case Type::Category::Void:
 	default:
 		break;
-		//BOOST_THROW_EXCEPTION(dev::Exception() << errinfo_comment("Unsupported solidityType: " + _type->toString()));
 	}
 	return r;
 }
diff --git a/mix/QVariableDeclaration.cpp b/mix/QVariableDeclaration.cpp
index 7a08da116..391d26c04 100644
--- a/mix/QVariableDeclaration.cpp
+++ b/mix/QVariableDeclaration.cpp
@@ -14,8 +14,9 @@
 	You should have received a copy of the GNU General Public License
 	along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
 */
-/** @file QVariableDeclaration.h
+/** @file QVariableDeclaration.app
  * @author Yann yann@ethdev.com
+ * @author Arkadiy Paronyan arkadiy@ethdev.com
  * @date 2015
  */
 
diff --git a/mix/QVariableDeclaration.h b/mix/QVariableDeclaration.h
index 3fcc00dcc..cf9345061 100644
--- a/mix/QVariableDeclaration.h
+++ b/mix/QVariableDeclaration.h
@@ -37,6 +37,7 @@ namespace dev
 namespace mix
 {
 
+/// UI wrapper around solidity type
 class QSolidityType: public QObject
 {
 	Q_OBJECT
@@ -49,7 +50,7 @@ public:
 	QSolidityType() {}
 	QSolidityType(QObject* _parent, SolidityType const& _type);
 	using Type = SolidityType::Type;
-	enum QmlType //TODO: arrays and structs
+	enum QmlType //TODO: Q_ENUMS does not support enum forwarding. Keep in sync with SolidityType::Type
 	{
 		SignedInteger,
 		UnsignedInteger,
@@ -72,6 +73,7 @@ private:
 	SolidityType m_type;
 };
 
+/// UI wrapper around declaration (name + type)
 class QVariableDeclaration: public QBasicNodeDefinition
 {
 	Q_OBJECT
diff --git a/mix/SolidityType.h b/mix/SolidityType.h
index c35f4285d..9990e2e7f 100644
--- a/mix/SolidityType.h
+++ b/mix/SolidityType.h
@@ -33,13 +33,14 @@ namespace mix
 
 struct SolidityDeclaration;
 
+//Type info extracted from solidity AST
 struct SolidityType
 {
-	enum Type //TODO: arrays and structs
+	enum Type //keep in sync with QSolidity::Type
 	{
 		SignedInteger,
 		UnsignedInteger,
-		Hash,
+		Hash, //TODO: remove
 		Bool,
 		Address,
 		Bytes,
@@ -47,12 +48,12 @@ struct SolidityType
 		Struct
 	};
 	Type type;
-	unsigned size; //bytes,
+	unsigned size; //in bytes,
 	bool array;
 	bool dynamicSize;
 	QString name;
-	std::vector<SolidityDeclaration> members;
-	std::vector<QString> enumNames;
+	std::vector<SolidityDeclaration> members; //for struct
+	std::vector<QString> enumNames; //for enum
 };
 
 struct SolidityDeclaration
diff --git a/mix/qml/StructView.qml b/mix/qml/StructView.qml
index cbd457947..021365ac8 100644
--- a/mix/qml/StructView.qml
+++ b/mix/qml/StructView.qml
@@ -8,7 +8,6 @@ Column
 	id: root
 	property alias members: repeater.model  //js array
 	property var value : { x: "333" }
-	property int level: 0
 	Layout.fillWidth: true
 
 	Repeater
@@ -65,7 +64,6 @@ Column
 					var pname = members[index].name;
 					var vals = value;
 					if (ptype.category === QSolidityType.Struct && !item.members) {
-						item.level = level + 1;
 						item.value = getValue();
 						item.members = ptype.members;
 					}
diff --git a/mix/qml/TransactionDialog.qml b/mix/qml/TransactionDialog.qml
index 64d62de69..5d98d3dbd 100644
--- a/mix/qml/TransactionDialog.qml
+++ b/mix/qml/TransactionDialog.qml
@@ -11,7 +11,7 @@ Window {
 	id: modalTransactionDialog
 	modality: Qt.ApplicationModal
 	width: 520
-	height: 500;//(paramsModel.count > 0 ? 500 : 300)
+	height: 500;
 	visible: false
 	color: StateDialogStyle.generic.backgroundColor
 	title: qsTr("Edit Transaction")
@@ -25,7 +25,6 @@ Window {
 	property var paramsModel: [];
 	property bool useTransactionDefaultValue: false
 	property alias stateAccounts: senderComboBox.model
-
 	signal accepted;
 
 	function open(index, item) {
@@ -87,6 +86,9 @@ Window {
 
 		visible = true;
 		valueField.focus = true;
+		modalTransactionDialog.height = (paramsModel.length > 0 ? 500 : 300);
+		paramLabel.visible = paramsModel.length > 0;
+		paramScroll.visible = paramsModel.length > 0;
 	}
 
 	function loadFunctions(contractId)
@@ -326,16 +328,15 @@ Window {
 				id: paramLabel
 				text: qsTr("Parameters:")
 				Layout.preferredWidth: 75
-				visible: true;//paramsModel.length > 0
 			}
 
 			ScrollView
 			{
+				id: paramScroll
 				anchors.top: paramLabel.bottom
 				anchors.topMargin: 10
 				Layout.fillWidth: true
 				Layout.fillHeight: true
-				visible: true;//paramsModel.length > 0
 				StructView
 				{
 					id: typeLoader
diff --git a/mix/qml/VariablesView.qml b/mix/qml/VariablesView.qml
index 36105da9e..191ec52af 100644
--- a/mix/qml/VariablesView.qml
+++ b/mix/qml/VariablesView.qml
@@ -32,7 +32,7 @@ DebugInfoList
 	function setData(members, values)  {
 		storage.item.value = {};
 		storage.item.members = [];
-		storage.item.value = values;
+		storage.item.value = values; //TODO: use a signal for this?
 		storage.item.members = members;
 	}
 }