How do I go back to previous screen?

[shelby]

When I click on NEXT, I'll do some condition check. If failed I do not want to proceed to the next screen. How do I do that?

[Darryl]

Re: How do I go back to previous screen?

There's a built-in variable that can be used for this purpose. It's defined as follows:

%PreventNextPage%
This is a special variable that can be set on a screen's Before or After action tabs. If this variable is set to TRUE, the installer will not allow the user to proceed to the next screen when the Next button is clicked; instead, the user will remain on the current screen. If set to FALSE, the installer will allow the user to proceed normally when they click Next.

This variable is useful if you want to validate the data entered by the user on a screen. If the data is incorrect, you could display an error message and set %PreventNextPage% to "true" to make the user go back and enter valid data.

The value of %PreventNextPage% is reset to FALSE every time a screen is displayed.