Searching For Index Of Object In Array?

I'm trying to search an object array for a particular object and return the index. g always ends up being -1 even though I'm expecting it to be 0. What am I missing?

Private Sub btnX1_Click(sender As System.Object, e As System.EventArgs) Handles btnX1.Click
Dim g As SByte = Array.IndexOf(buttons, sender)
MsgBox("If worked: " & g, MsgBoxStyle.OkOnly, "Test")
End Sub
dim buttons() as object = {btnX1, btnX2, btnX3}

Basically, I'm trying to design a function that can get the index of an element from one object array and use that to grab an element from a different array at that same index.