diff --git a/src/main.tsx b/src/main.tsx
index 1b6cb2ac..1c3d248b 100644
--- a/src/main.tsx
+++ b/src/main.tsx
@@ -1040,7 +1040,7 @@ class ScreenWindowView extends React.Component<{sw : ScreenWindow}, {}> {
     renderError(message : string) {
         let {sw} = this.props;
         return (
-            <div className="window-view" style={this.getWindowViewStyle()} id={this.getWindowViewDOMId()}>
+            <div className="window-view" style={this.getWindowViewStyle()} id={this.getWindowViewDOMId()} data-windowid={sw.windowId}>
                 <div key="window-tag" className="window-tag">
                     <span>{sw.name.get()}{sw.shouldFollow.get() ? "*" : ""}</span>
                 </div>
@@ -1124,7 +1124,7 @@ class ScreenView extends React.Component<{screen : Screen}, {}> {
             );
         }
         return (
-            <div className="screen-view">
+            <div className="screen-view" data-screenid={sw.screenId}>
                 <ScreenWindowView key={sw.windowId} sw={sw}/>
             </div>
         );
@@ -1197,7 +1197,7 @@ class SessionView extends React.Component<{}, {}> {
         }
         let activeScreen = session.getActiveScreen();
         return (
-            <div className="session-view">
+            <div className="session-view" data-sessionid={session.sessionId}>
                 <ScreenView screen={activeScreen}/>
                 <ScreenTabs session={session}/>
                 <CmdInput/>
diff --git a/src/model.ts b/src/model.ts
index cde8f2b4..2912ce37 100644
--- a/src/model.ts
+++ b/src/model.ts
@@ -284,7 +284,7 @@ class ScreenWindow {
         if (activeScreen == null) {
             return false;
         }
-        return (this.sessionId = activeScreen.sessionId) && (this.screenId == activeScreen.screenId);
+        return (this.sessionId == activeScreen.sessionId) && (this.screenId == activeScreen.screenId);
     }
 
     colsCallback(cols : number) : void {
@@ -1172,6 +1172,21 @@ class Model {
         getApi().onDigitCmd(this.onDigitCmd.bind(this));
     }
 
+    dumpStructure() : void {
+        for (let i=0; i<this.sessionList.length; i++) {
+            let session = this.sessionList[i];
+            console.log("SESSION", session.sessionId);
+            for (let j=0; j<session.screens.length; j++) {
+                let screen = session.screens[j];
+                console.log("  SCREEN", screen.sessionId, screen.screenId);
+                for (let k=0; k<screen.windows.length; k++) {
+                    let win = screen.windows[k];
+                    console.log("    WINDOW", win.sessionId, win.screenId, win.windowId);
+                }
+            }
+        }
+    }
+
     getTUR(sessionId : string, cmdId : string, cols : number) : number {
         let key = sessionId + "/" + cmdId + "/" + cols;
         return this.termUsedRowsCache[key];