How to display an error message if dropdown list is null

Question

I have a dropdown that displays nothing. If I hit the save button and nothing is displayed I want an error message stating something has to be selected

I've tried if ddl.POApprover.text = "" then display the message but that doesn't display

If ddlPOApprover.Text = "" And (Session("UserGroup") = 13) Then
            MsgBox("Error: An Approver must be provided before you can save")
            blnValidation = False
        End If

I want the error to come up when I hit save but it doesn't

I see you are using `Session` in there. Does that mean it's an ASP.NET program? If so, the message box will appear on the server, which is probably not what you intended. — Andrew Morton, Sep 18 '19 at 10:18
...but you could use [How can I display a messagebox in ASP.NET?](https://stackoverflow.com/questions/15196381/how-can-i-display-a-messagebox-in-asp-net) — Andrew Morton, Sep 18 '19 at 10:23
Either way, you need to set [`Option Strict On`](https://stackoverflow.com/a/29985039/1115360) and correct the problems it points out for you. — Andrew Morton, Sep 20 '19 at 08:16

score 1 · Answer 1 · edited Sep 17 '19 at 19:01

1

It's If ddlPOApprover.SelectedValue not .Text

edited Sep 17 '19 at 19:01

ADyson

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answered Sep 17 '19 at 16:22

NoLuckCollector

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OctaCode · Answer 2 · 2019-09-20T07:40:47.253

A Combobox has an array from 0 to numberOfItems -1. whenever there is nothing selected, it's index is -1 so you can check if ddlPOApprover.selectedindex < 0 then no item has been chosen

Edit: i also want you to try replacing And with AndAlso like: If ddlPOApprover.Text = "" AndAlso (Session("UserGroup") = 13) Then would it still give you an error? if not then you can choose either my main answer or leave it and just change And to AndAlso

How to display an error message if dropdown list is null

2 Answers2