# ASP.NET valid XHTML

**URL:** <https://forum.kirupa.com/t/asp-net-valid-xhtml/228038>\
**Category:** programming\
**Created:** [June 4, 2007, 8:53pm UTC](https://forum.kirupa.com/t/asp-net-valid-xhtml/228038 "2007-06-04T20:53:40Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![rewko](https://avatars.discourse-cdn.com/v4/letter/r/b38774/32.png) [@rewko](https://forum.kirupa.com/u/rewko)\
**Post date:** [June 4, 2007, 8:53pm UTC](https://forum.kirupa.com/t/asp-net-valid-xhtml/228038/1 "2007-06-04T20:53:40Z")

</div>

Hello,

I am trying to create simple web form in Visual Studio. But any form is not valid HTML. Tidy validator ([http://tidy.sourceforge.net](http://tidy.sourceforge.net)) says there is a warning

```php
Warning: <input> ID "__VIEWSTATE" uses XML ID syntax

```

Does anybody know solution? How to create Warning free XHTML form in .NET?

btw [http://www.kirupafx.com/HelloWorld/Default.aspx](http://www.kirupafx.com/HelloWorld/Default.aspx) has the same warning.

Thanks