C# - usage of static class

Below is an example of using "static class" in C#:

Ref.: http://msdn.microsoft.com/en-us/library/79b3xss3(VS.80).aspx

Main class()
{
...

public static class UtilFunc
{
private static string g_strLogFileURL = "test";

public static void SetLogDir(string strURL)
{
if (strURL != "") g_strLogFileURL = strURL;
}

public static string LogToFile()
{
return g_strLogFileURL;
}
}
...
}

Other Class()
{
....

// static class can't be instantiated, simply use its APIs as below
MessageBox.Show(UtilFunc.LogToFile());

....
}