Error: Syntax eror conerting the varchar value '[12] FirstName LastName' to a column of data type int

Codebits:
****************
' Declare the protected objects
Protected WithEvents drpSalesman As DropDownList

Protected WithEvents txtDate As TextBox
Protected WithEvents txtAmount As TextBox

Protected WithEvents lblDebug As Label

Protected WithEvents pnlForm As Panel
Protected WithEvents pnlConfirm As Panel
Protected WithEvents pnlDone As Panel

Protected WithEvents lblSalesman As Label
Protected WithEvents lblDate As Label
Protected WithEvents lblAmount As Label

'Gobal Vars

Public conSQL As New SqlConnection( ConfigurationSettings.AppSettings( "ConnectionString" ) )
Public cmdSQL As SqlCommand
Public dtrSQL As SqlDataReader

************
Sub SendSMS()
Dim strSQL As String = ""
Dim strMessage As String = ""

strMessage &= "Compliance: " & drpSalesman.SelectedItem.Text & " $ " & String.Format("{0:#,###}", CInt(txtAmount.Text)) & vbCrLf

'''''''''''''''''''''''''''''''''''''''
'Saleperson Day Total
'''''''''''''''''''''''''''''''''''''''
strSQL = "SELECT "
strSQL &= "SUM(amount) as total "
strSQL &= "FROM "
strSQL &= "SB_data as sb "
strSQL &= "WHERE user_id = '" & drpSalesman.SelectedItem.Value & "' AND datestamp > '" & Now.ToString("d") & "' "


conSQL.Open()
cmdSQL = New SqlCommand(strSQL, conSQL)
dtrSQL = cmdSQL.ExecuteReader()

Line 160 If dtrSQL.Read() Then
strMessage &= drpSalesman.SelectedItem.Value & " Day Total: $ " & String.Format("{0:#,###}", dtrSQL("total")) & vbCrLf
End If

dtrSQL.Close()

conSQL.Close()
*****************
Line 160 is where the error is reported to occur.

Any help with this would be greatly appreciated.