If you ever tried adding Google Search code that will search your site to a SharePoint page using the HTML Form web part, you might get an error like this:

Unexpected System.NullReferenceException: Object reference not set to an instance of an object.   at Microsoft.SharePoint.WebPartPages.WikiPageWebPartSaver.SaveWebPartsInRichText(SPWebPartManager wpmgr)

A simple way to add the Google Search for your site is to use the Page Viewer Web Part and reference an HTML file with the Google Search form code:

 <!-- Search Google --> 
<font color="#006633" size="+1" face="Times New Roman">Search</font> 
<center> 
<FORM action=http://www.google.com/u/ursite method=GET target="_blank"> 
<!--mstheme--></font>
<TABLE bgcolor=#FFFFFF cellspacing=0 border=0><tr valign=middle><td><!--mstheme--><font face="Times New Roman"> 
<A HREF=http://www.google.com/ > 
<IMG SRC="http://www.google.com/logos/Logo_40wht.gif" border=0 ALT=Google width="128" height="53"></A> <!--mstheme--></font></td> 
<td><!--mstheme--><font face="Times New Roman"> 
<INPUT TYPE=text name=q size=31 maxlength=255 value=""> 
<INPUT type=submit name=sa VALUE="Google Search" > 
<input type=hidden name=hq value="inurl:www.YourSite.com/subsite" > 
<font face=arial,sans-serif size=-1><br><input type=hidden name=sitesearch value="YourSite.com" checked> 
</font><br> 
<!--mstheme--></font></td></tr></TABLE>
<!--mstheme--><font face="Times New Roman">    
</FORM> 
</center> 
<!-- Search Google --> 

Add the file to the sub folder under LAYOUTS:  \Web Server Extensions\14\TEMPLATE\LAYOUTS\Custom\google.html

Then, add a Page Viewer Web Part (Under Media and Content) to a page and set the Web Page property to http://ServerName/_layouts/custom/google.html

Note: You may have to allow the search to open in a new window.

When someone asks, “What is SharePoint?” it is difficult to give a comprehensive answer, but this excellent article about SharePoint on MSDN does a pretty good job.

In a custom version of the ContentByQueryWebPart, the items that were displayed from a list were not being sorted in any meaningful way.  The default sort is the created date.  To fix this, there are a few properties that needed to be added in the implementation using the object model approach.  The properties are “SortBy”, “SortDirection”, and “SortByFieldType.”  Here is how this is done in code and note that the “SortBy” field is not the title of the field name but the item ID:

public class CoolNav : ContentByQueryWebPart
    {
            static string listGuid = String.Empty;
            static string url = String.Empty;
            static string itemStyle = "LinkList";
            static SPList list; 

            public CoolNav() : base()
            {
                if (listGuid == String.Empty)
                {
                    listGuid = SPContext.Current.Site.RootWeb.Lists["Cool Navigation"].ID.ToString();
                    list = SPContext.Current.Site.RootWeb.Lists["Cool Navigation"];
                }

                if (url == String.Empty)
                {
                    url = SPContext.Current.Site.ServerRelativeUrl;
                }
            }
            protected override void OnLoad(EventArgs e)
            {
                base.OnLoad(e);
                this.ListGuid = listGuid;
                this.WebUrl = url;
                // Sort Properties
                this.SortBy = list.Fields["Order"].Id.ToString();
                this.SortByDirection = SortDirection.Asc;
                this.SortByFieldType = "Number";
                String ServerURL = SPContext.Current.Site.ServerRelativeUrl;
                //Fix the URL Path
                if (!ServerURL.EndsWith(@"/"))
                    ServerURL += @"/";
                this.MainXslLink = ServerURL + @"Style Library/XSL Style Sheets/CoolNav.xsl";
                this.ItemXslLink = ServerURL + @"Style Library/XSL Style Sheets/CoolNav_ItemStyle.xsl";
                this.ItemStyle = itemStyle;
                this.CommonViewFields = "URL,text";
            }
     }

Two ways to do check if a SharePoint list exists (that I know of)…

1. Put it in a Try/Catch block

        /// <summary>
        /// Utility function to check if a list exists
        /// </summary>
        private static bool DoesListExist(SPWeb web, string listName)
        {
            try
            {
                SPList list = web.Lists[listName];
            }
            catch
            {
                return false;
            }
            return true;
        }

2. Use the TryGetList function from SPListCollection:

if (SPContext.Current.Site.RootWeb.Lists.TryGetList(ListName) != null)
{
     DoStuff();
}