Calling a sub Function / Module from two different VB (excel) modules

I have a function that I want to call from a variety of modules. Whats the best way to do this in VB (excel).

module "SheetExists"

Function Name(SheetName As String) As Boolean
' returns TRUE if the sheet exists in the active workbook
    SheetExists = False
    On Error GoTo NoSuchSheet
    If Len(Sheets(SheetName).Name) > 0 Then
        SheetExists = True
        Exit Function
    End If
NoSuchSheet:
End Function

module "Main"

If Not SheetExists.Name("mySheet") Then
    'do this
Else
    ' else do this
End If

I DONT want to have to do this or do I??

Call SheetExists.Name("mySheet")

Is that the only way to call a function from another module? Do I have to declare it as a Public function or something?