Could not load type 'System.Web.UI.Compatibility.CompareValidator' from assembly 'System.Web.Extensions' Issue Fixing

Things were working good but after installing ASP.NET AJAX 1.0 I was Getting most probably this error


FIXES Bellow

Step 1. I have downloaded validators from:
http://blogs.msdn.com/mattgi/attachment/1516974.ashx

Step 2. I had below mappings in web.config:
Step 2. I had below mappings in web.config:
<tagMappingglt;
<add tagType="System.Web.UI.WebControls.CompareValidator" mappedTagType="System.Web.UI.Compatibility.CompareValidator, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/glt;
<add tagType="System.Web.UI.WebControls.CustomValidator" mappedTagType="System.Web.UI.Compatibility.CustomValidator, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/glt;
<add tagType="System.Web.UI.WebControls.RangeValidator" mappedTagType="System.Web.UI.Compatibility.RangeValidator, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/glt;
<add tagType="System.Web.UI.WebControls.RegularExpressionValidator" mappedTagType="System.Web.UI.Compatibility.RegularExpressionValidator, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/glt;
<add tagType="System.Web.UI.WebControls.RequiredFieldValidator" mappedTagType="System.Web.UI.Compatibility.RequiredFieldValidator, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/glt;
<add tagType="System.Web.UI.WebControls.ValidationSummary" mappedTagType="System.Web.UI.Compatibility.ValidationSummary, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/glt;
</tagMappingglt;

Replaced above with :
<tagMappingglt;
<add tagType="System.Web.UI.WebControls.CompareValidator" mappedTagType="Sample.Web.UI.Compatibility.CompareValidator, Validators, Version=1.0.0.0"/glt;
<add tagType="System.Web.UI.WebControls.CustomValidator" mappedTagType="Sample.Web.UI.Compatibility.CustomValidator, Validators, Version=1.0.0.0"/glt;
<add tagType="System.Web.UI.WebControls.RangeValidator" mappedTagType="Sample.Web.UI.Compatibility.RangeValidator, Validators, Version=1.0.0.0"/glt;
<add tagType="System.Web.UI.WebControls.RegularExpressionValidator" mappedTagType="Sample.Web.UI.Compatibility.RegularExpressionValidator, Validators, Version=1.0.0.0"/glt;
<add tagType="System.Web.UI.WebControls.RequiredFieldValidator" mappedTagType="Sample.Web.UI.Compatibility.RequiredFieldValidator, Validators, Version=1.0.0.0"/glt;
<add tagType="System.Web.UI.WebControls.ValidationSummary" mappedTagType="Sample.Web.UI.Compatibility.ValidationSummary, Validators, Version=1.0.0.0"/glt;
</tagMappingglt;