focus on Listbox

Hi Guys

I have two Listboxs Listbox1 and Listbox2

When the program runs the first items in both boxes are highlighted by using

ListBox1.SetSelected(0, True)
ListBox2.SetSelected(0, True)

While they are highlighted i need Listbox2 to have focus so that I can use the scroll wheel to scroll through the list. I have to click on the item to allow me to use the wheel to scroll

Is there any way of making the highlighted item as if it was clicked automatically so that I don't have to click it manual

Thanks for your help

Mark