How to Fix the Default Form Button Issue in Firefox for ASP.NET Controls

If you are developing a web application using ASP.NET and have run into a frustrating issue where your default button inside a server control works in Internet Explorer and Safari but not in Firefox, you are not alone. In this post, we will explore a common problem that occurs when the default button is not triggered appropriately in Firefox, along with a straightforward solution to resolve it.

Understanding the Problem

When you create a server control in ASP.NET that includes a button for triggering a search, you typically set the default button behavior for that form. This is done using the following code snippets:

Setting Default Button on the Panel:

MyPanel.DefaultButton = SearchButton.ID

Setting Default Button in the Control:

Me.Page.Form.DefaultButton = SearchButton.UniqueID

In theory, this configuration allows users to enter their search term and submit the form by simply hitting the “Enter” key, effectively executing the search process. However, a peculiar issue arises in Firefox where users encounter an alert box stating:

“Object reference not set to an instance of an object.”

This frustrating error indicates that Firefox is unable to properly reference the button when submitting the form, resulting in a failure of the intended action.

The Solution

Fortunately, there is a simple fix for this issue. By adjusting the behavior of the button, you can allow Firefox to handle the default button submission without throwing an error. Here’s how you can do it:

Step 1: Modify Button Behavior

Add the following line to your button’s configuration:

SearchButton.UseSubmitBehavior = False

Why This Works

By setting UseSubmitBehavior to False, you effectively make the button behave differently, allowing it to bypass the default behavior that Firefox struggles with. This adjustment replaces the default behavior with more manageable actions that are compatible with all browsers.

Conclusion

Browser compatibility is a key consideration in web application development, and sometimes small changes can lead to significant improvements in functionality. If you find yourself facing similar issues with Default Form Buttons in Firefox, applying the simple solution above should set you on the right path to ensure a seamless user experience across all browsers.

By implementing the recommended change to UseSubmitBehavior, you can enhance your application’s reliability and make the interaction smoother for your users. Don’t hesitate to share your experiences or other tips related to ASP.NET forms in the comments below!