Update app.py

app.py

@@ -8,6 +8,9 @@ openai_api_key = os.getenv("OPENAI_API_KEY")
 st.title("💬 Chatbot")
 st.caption("")
 
+# Select model using a dropdown
+model_choice = st.selectbox('Choose a model:', ['gpt-3.5-turbo', 'gpt-4-turbo'])
+
 # Initialize session state for storing messages if it doesn't already exist
 if "messages" not in st.session_state:
     st.session_state["messages"] = [{"role": "assistant", "content": "How can I help you?"}]
@@ -38,5 +41,4 @@ if prompt:
     st.session_state.messages.append({"role": "assistant", "content": msg})
     st.chat_message("assistant").write(msg)
 
-    # Select model using a dropdown
-    model_choice = st.selectbox('Choose a model:', ['gpt-3.5-turbo', 'gpt-4-turbo'])
+