getting error at using using Googlemarker like this Error 1 The type or namespace name 'Googlemarker' could not be found (are you missing a using directive or an assembly reference?)

<asp:Label ID="AddressLabel" runat="server" Text="Enter address:" /> <asp:TextBox ID="AddressTextBox" runat="server" /> <asp:Button ID="DisplayButton" runat="server" Text="Display Location" onclick="DisplayButton_Click" /><br /><br /> <cc1:GoogleMap ID="SampleGoogleMap" runat="server"> </cc1:GoogleMap>

using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using Googlemarker;
protected void DisplayButton_Click(object sender, EventArgs e) { DisplayMap(); } private void DisplayMap() { SampleGoogleMap.Key = AIzaSyD4k2ANXUvAuGzYbJj4dlrMYY1qHNKcjbA; SampleGoogleMap.Height = 600; SampleGoogleMap.Width = 600; SampleGoogleMap.Address ...