Directory Chooser - when is the value available?

For my installer, I have built a dialog in the Pre-Install section, using the standard Get User Input -Advanced panel. In that I am using a Directory Chooser component to allow the user to select a folder where the product should be installed. The value is stored in IA's $USER_INSTALL_DIR$ variable.

Right below the Directoy Chooser component, I have a Label component whose value is set to $USER_INSTALL_DIR$\subComponent - with intention that the user can see where sub-components will be installed.

When I run the installer, the Directory Chooser shows the default install location, and so does the label. However, when I select a custom location, the value of the label does not change. I have to navigate to the next panel and come back to this panel to see the changed value of the label.

How can I use the value of $USER_INSTALL_DIR$ right away after the user selects the custom location?

Regards,
Shailesh.

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