Save image(in picture box) in to a file

Hi,
I done code for free hand drawing in ASP.Net C#(Windows App).I have to store that image in DB when I clicking that button. But i don't have idea about it.Help me guys... I draw th image in picture box. The code for save button is following:

ImageFormat format = ImageFormat.Jpeg;

SaveFileDialog sfd = new SaveFileDialog();

sfd.Filter = "Jpeg Format(*.Jpeg)|*.Jpeg";

if (sfd.ShowDialog() == DialogResult.OK)

{

//shapePB.Image.Save(sfd.FileName, System.Drawing.Imaging.ImageFormat.Jpeg);

shapePB.Image.Save(sfd.FileName, format);

}

Here shapePB is a pictureBox.

Thanks in Advance

Kavisuja.M