▲请大虾们帮忙了！▲

[beniVBVB]

在将一个函数返回值赋给一个Session变量时出错：
Dim getDID As GetUserName
Session("DeptID") = getDID.GetDeptID(UserName) （提示该句错误）

错误信息是：
System.FormatException: 输入字符串的格式不正确

该函数如下：
Public Class GetUserName
Public Function GetDeptID(ByVal NowUserName As Integer) As Integer
Dim NowDID As String
Dim Conn As SqlConnection = New SqlConnection(ConfigurationSettings.AppSettings("Appas.SqlConnStr"))
Dim SQL As String = "Select DeptID from Auth_User where UserName='" & NowUserName & "'"
Conn.Open()
Dim CMD As SqlCommand = New SqlCommand(SQL, Conn)
CMD.CommandTimeout = 15
CMD.CommandType = CommandType.Text
NowDID = CMD.ExecuteScalar
Conn.Close()
Return NowDID
End Function
End Class

请各位帮助，多谢了！

[cmsoft]

Public Function GetDeptID(ByVal NowUserName As String) As Integer

[cmsoft]

ByVal NowUserName As String不是As Integer