# Building your First Mobile App: App Logic
The app logic is responsible for toggling the visibility of the image and updating the button text accordingly. Follow these steps to implement the logic:
App logic
1. Navigate to the **`Blocks`** tab above the **`Properties`** panel.
2. Click on **`Button1`** in the `Blocks` panel and drag the **`when Button1.Click`** block.
3. Drag an **`if then else`** block from the **`Control`** section into the **`when Button1.Click`** block.
4. Drag an equal block from the **`Logic`** section and drop it into the if statement.
5. Use the **`Button1.Text`** block from the **`Button1`** section, placing it in the first section of the equal operation.
6. Drag an empty text block from the **`Text`** section into the second part of the equal operation. Type *Hide* in the empty block.
App condition
7. Click on the **`Image1`** block and drag and drop **`set Image1.Visible to`** on your screen. From the **`Logic`** section grab the **`False`** block. Connect them together.
8. Similarly, click on the **`Button1`** block and drag and drop **`set Button1.Text to`** on your screen. From the **`Text`** section grab the empty text block and type `S`**`how`****.** Connect them together.
9. Move these two blocks inside the if statement.
Completed if block
10. Right-click on the first set block, choose **`Duplicate`**, and move the duplicated block inside the else statement. Change **`False`** to **`True`** and **`Show`** to **`Hide`**.
11. Duplicate the other block, move it into the else statement, and change the text to **`Hide`**. The final code is as follows:
Final code
12. **Congratulations, you are done!** Test your app to see the logic in action.
---
# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://caseytechschool.gitbook.io/app-development-using-mit-app-inventor-platform/tutorial-1-image-hide-and-seek/building-your-first-mobile-app-app-logic.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.
