---
title: "DropDown List Validation"  
description: "DropDown List Validation"  
author: "Anonymous User"  
published: 2014-08-23  
updated: 2014-08-23  
canonical: https://www.mindstick.com/forum/2106/dropdown-list-validation  
category: "asp.net"  
tags: ["asp.net"]  
reading_time: 1 minute  

---

# DropDown List Validation

I need to perform a [validation](https://www.mindstick.com/articles/12234/validation-using-data-annotation-using-entity-framework) to [check whether](https://www.mindstick.com/forum/157543/write-a-java-program-to-check-whether-a-string-is-a-palindrome) a [TextBox](https://www.mindstick.com/forum/12714/dynamic-textbox-in-gridview) [value](https://www.mindstick.com/articles/23219/an-optimized-description-adds-value-to-experience-and-in-turn-effectively-guest-posting-packages) is empty on Dropown list selected [Index](https://www.mindstick.com/blog/198/index-in-sql-server) change using validation [controls](https://www.mindstick.com/articles/66/how-to-create-controls-at-run-time-in-csharp-dot-net) in [asp.net](https://www.mindstick.com/articles/934/default-folders-available-inside-the-asp-dot-net-application-folder)

## Replies

### Reply by Sumit Kesarwani

Hi Ankita, \

I hope this will work fine.

```
    <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>   
<asp:DropDownList ID="DropDownList1" runat="server" CausesValidation="true"
AutoPostBack="true">    </asp:DropDownList><asp:RequiredFieldValidator ID="RequiredFieldValidator1" ControlToValidate="TextBox1"
runat="server" ErrorMessage="Please Enter the Value"></asp:RequiredFieldValidator>
```


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Original Source: https://www.mindstick.com/forum/2106/dropdown-list-validation

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