How can we add custom logic while installing exe created by installshield

Question

Is there any way to add custom logic which should be executed while installing the application created by installshield wizard ? Logic i need to implement includes checking internet connection and searching for key in registry ,if the conditions are valid then continue installing application else show message to user and stop installation . i have searched for options in installshield wizard but i didn't find any solution. I even made a logic diagram

By the way i am using vb6 .

Answer 1

After some research i ended up with the installscript solution . In installshiled we can add InstallScript and sequence it in different event , for checking internet connection and registry value etc ..i made a custom dll to check my logic and called it via installscript . this link will be useful if we have to call dll function via installscript.Here is code snippet to use dll function in installscript

prototype [CallingConvention] [ReturnType] DLLName.FunctionName( ParamType1, ParamType2, ... );

For example:

prototype BOOL ConnectionCheckdll.CheckInternetConnection( INT, INT, INT );
UseDLL( SUPPORTDIR ^ "ConnectionCheckdll.dll" );
bResult = ConnectionCheckdll.CheckInternetConnection( nInt1, nInt2, nInt3 );
UnUseDLL( SUPPORTDIR ^ "ConnectionCheckdll.dll" );