i have this code in my btnsave..it can detect conflicts but after that a dialog box saying:
An unhandled exception of type 'System.NullReferenceException' occurred in AppointmentSchedulingClient.exe
Additional information: Object reference not set to an instance of an object.
and it points to the green one below.
If Val(cbostart.Text) > Val(cboend.Text) Or Val(cbostart.Text) = Val(cboend.Text) Then
MsgBox("Error in time.", MsgBoxStyle.Information, "MESSAGE")
Else
open_con2()
sqlsearch = "Select *from tblappointreserv"
cmd2 = New OleDbCommand(sqlsearch, con2)
dr = cmd2.ExecuteReader
While dr.Read
Dim date, startime, endtime, d As String
date = dtpdate.Text = dr("Whendate")
startime = cbostart.Text = dr("Startime")
endtime = cboend.Text = dr("Endtime")
d = startime = True And endtime = True
If d = True And date = True Then
MsgBox( "Sorry your appointment can't be reserve. Conflict has been detected.", MsgBoxStyle.Information, "MESSAGE")
End If
dr.Close()
dr = Nothing
End While
End If
i still have the SQlInsert below that.. but this thing sucks me.. please help me..