select/highlight area on image on textbox focus

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C#

ASP.NET

Javascript

C#4.0

Hi All,

I am working on a C# web application. I need to select/highlight some area on an image on focus of a textbox, and then de-select the area when the focus is lost. I have been able to do so on click of a button, by using bitmap and Graphics object. But I cant do the same on textbox onfocus event.

I had used the following code written inside a static server side function :

Bitmap bmp = (Bitmap)Bitmap.FromFile("~/Images/SampleDoc.jpg");
Graphics g = Graphics.FromImage(bmp);

Pen snowPen = new Pen(Color.Blue, 2);
g.DrawRectangle(snowPen, 600, 225, 100, 30);
//g.DrawRectangle(Pen, x, y, width, height);

String path = Server.MapPath("~/Images/DrawRectangle.jpg");
bmp.Save(path, ImageFormat.Jpeg);

Image1.ImageUrl = "~/Images/DrawRectangle.jpg";
g.Dispose();
bmp.Dispose();

and called it using a javascipt function.

I tried using the code above for a textbox focus too but I wasn't able to access the Server object and Image1 object.

I am pretty new to asp.net and javascript. Any help will be much appreciated.

Thanks in advance.

Gitika Khurana