Scripting - app.executeCommand(3000)

Hey Guys,

I have a button linked to a function. Please see below.

The app.executeCommand(3000) is to launch the create new 'Solid' diagloue box which it does. However when it does this The option to 'make Comp Size' is greyed out. Please see attached image.

Is this any reason for this or is there another way to launch that dialogue and to have that option availible? 

btnSolid.onClick = function() {
    if (app.project.activeItem == undefined || app.project.activeItem == null) {
        alert("Please Select a Composition");
        return false;
    } else {
        app.executeCommand(3000);
    }
}

Thanks,

Liam