VB.NET Generic Function

What I want to do is, based on the type of T do different opperations. Below is a simple example of my problem.

Public Shared Function Example(Of T)() As T
    Dim retval As T
    If TypeOf retval Is String Then
        Dim myString As String = "Hello"
        retval = myString
    ElseIf TypeOf retval Is Integer Then
        Dim myInt As Integer = 101
        retval = myInt
    End If
    Return retval
End Function

I get the error "Value of Type 'String' Cannot be converted to 'T'" Same with the integer part. If I cast either to an object before asigning them to retval it works but I think that would defeat my purpose and be less efficient. Any Ideas? Thanks!