xfa.host.messageBox - Break the script with a return value

[goneforgolddamo]

I have a message box with a YES/NO answer.

If No is the return value, I would like to stop the script.

Is there a way of doing this?

Here is my script:

if (xfa.host.messageBox("The manifest has already been created! Do you wish to continue?","Create Manifest",2,2)=="3")

     {

     break;

     }

I am not sure if 'Break' is the right code.

Hope someone can help me please!

BTW, I am using Adobe Designer v7.0