MS SQL Function Return String - What Am I Doing Wrong?

Cannot see where I am going wrong. I always get a value of 0. I know my function works correctly, so it must be the VB.


CREATE FUNCTION [dbo].[getNextProjectID] ()
RETURNS varchar(10) AS
BEGIN
'''''''''''''''''''...........................
DECLARE @vNextProjectID varchar(10)
RETURN @vNextProjectID
END


Sub LoadNextProjectNumber()
        Dim vProjectID As String
        Dim cmd As New SqlClient.SqlCommand()
        cmd.Connection = sqlConn
        cmd.CommandText = "getNextProjectID"

        cmd.Parameters.Add("@vNextProjectID", vProjectID)
        cmd.Parameters("@vNextProjectID").Direction = ParameterDirection.ReturnValue

        cmd.ExecuteScalar()
        vProjectID = cmd.Parameters("@vNextProjectID").Value

        txtProjectID.Text = vProjectID

        cmd.Dispose()
End Sub