ActiveDialog.Evaluate("ListBox1")

is failing on my Excel 2000. In fact, ActiveDialog evaluates to Nothing.

Seeing you are in a click event for ListBox1, you simply need to use its name -
no need to try to look it up. E.g.

ReDim sSelection(1 To ListBox1.ListCount) As Single

The with statement is bad too. Even if I change it to

With ListBox1.List = Array("CSE", "LAW")

It still fails with a type mismatch. With statements can't be assignment
statements, this is actually trying to use the = as an equality check. But you
can't do an equality check between List and an Array.

No idea why you have a with statement anyway, you aren't making use of it.

I also note that you have a variable  called vSelection that is never defined.
Additionally, you set it in two statements. The first sets it to an array
(sSelection); the second sets it to false. This is not very nice code.

Lastly, please do not put "Urgent" in your message. While it might possibly be
urgent to you, it certainly isn't to us.