I used a function with global and local variable below is my code:
var aNumber = 100;
tweak();
function tweak()
{
    // This prints "undefined", because aNumber is also defined locally below.
    document.write(aNumber);
    if (false)
    {
        var aNumber = 123; 
    }
}
What is the work of tweak(); I didn't understand. Anyone can help me please with details?
