diff --git a/wwwroot/list-component.js b/wwwroot/list-component.js
index 4b51f3f..1265b85 100644
--- a/wwwroot/list-component.js
+++ b/wwwroot/list-component.js
@@ -3,17 +3,22 @@
 
 bricks.List = class extends bricks.VBox {
     constructor(opts) {
+        // Ensure opts has options property
+        if (!opts) opts = {};
+        if (!opts.options) opts.options = {};
+        
+        // Set default dimensions if not provided
+        if (!opts.options.width) opts.options.width = '100%';
+        if (!opts.options.height) opts.options.height = '100%';
+        
         super(opts);
+        
         this.data_url = opts.data_url || null;
         this.items = opts.items || [];
         this.item_template_url = opts.item_template_url || null; // URL to the item template .ui file
         this.itemHeight = opts.itemHeight || 50;
         this._loading = false;
         
-        // Set default dimensions
-        if (!this.options.width) this.options.width = '100%';
-        if (!this.options.height) this.options.height = '100%';
-        
         // Load data if provided
         if (this.data_url) {
             this.loadData();