GoDiagram Zooming

i’m new to GoDiagram, i’m using GoDiagram 2.4 for VS2005 ASP.NET Applications. in Goview control i loaded a background image and i want to zoom a particular are using area. i.e. when the user drags the mouse over the image the releases the mouse only the rectangle area must be zoom. which i’m unable to do it.
can any one suggest me the solution?

You just need to use the GoToolZooming tool.
Let’s say your ASPX page has the following WebControls:
<GoWeb:GoView id=“GoView1” runat=“server” Width=“488px” Height=“336px”></GoWeb:GoView>
<asp:Button id=“Button1” runat=“server” Width=“120px” Text=“Zoom View”></asp:Button>
Then your code-behind/beside page would define a GoView1.SessionStarted event handler to initialize the GoView.Document, and your Button1.Click event handler could do:
private void Button1_Click(object sender, System.EventArgs e) {
GoToolZooming tool = new GoToolZooming(GoView1);
tool.Modal = true;
GoView1.Tool = tool;