Google Earth Runtime Error

[kenryou]

Hi,

can anyone tell me why must I declare the variables
(string earthVersion, string pluginVersion, string apiVersion)
when using
webBrowserGe.Url = new Uri("http://earthapi.googlepages.com/geToCs.html");

or there will be a runtime error, whereas I do not need to declare it when I'm using a plugin, like,
private const string PLUGIN_URL =
@"http://earth-api-samples.googlecode.com/svn/trunk/demos/desktop-embedded/pluginhost.html";
private void Form1_Load(object sender, EventArgs e)
{
webBrowser1.Navigate(PLUGIN_URL);
webBrowser1.ObjectForScripting = this;
}

Is it because that the plugin has a declared variables in it? Thanks in advance