How to hide the INSTALLING PAGE when have custom silent

How to hide the INSTALLING PAGE when have custom silent.

I am custom the silent mode in my installer, and I want to skip /S parameter, and instead of /IS_SILENT to default parameter of the silent mode.

Function .onInit
    ${GetParameters} $0
    ClearErrors
    ${GetOptions} `$0` '/s' $1
    IfErrors 0 NOTIFY1
        Goto EXIT
    NOTIFY1:
        MessageBox MB_OK|MB_ICONINFORMATION|MB_TOPMOST 'Please use /IS_SILENT parameter in your command line.'
        Quit
    EXIT:
;
    ${GetParameters} $0
    ClearErrors
    ${GetOptions} `$0` '/IS_SILENT' $1
    IfErrors 0 NOTIFY2
        Goto START
    NOTIFY2:
        MessageBox MB_OK|MB_ICONINFORMATION|MB_TOPMOST 'Using /IS_SILENT parameter in the command line.'
    START:
FunctionEnd

All working fine, but it's alway show the INSTALLING PAGE WINDOW.

In my case, How to hide the INSTALLING PAGE WINDOW ?.

Thanks.