steps to debug standard Forms and class in Microsoft dynamics ax 2012

It depends on your requirement. If its list page form then you can debug it in its interaction class. If its normal form then follow these points.

1. Enable debugging in server configuration

2. Press F9 on the line of code you want to debug

3. You can also write break point keyword on the line of code you want to debug.

4. Restart the form

5. To debug line by line you can press F10 if you want to debug sub method then you can press F11.