<!--Place this under the <system.web> node-->
<httpRuntime executionTimeout="1200" maxRequestLength="30720" />

public static void ResizeImage()
{
    using (Bitmap src = new Bitmap(_ImgOriginal))
    {
        int destWidth = (int)(0.5 * src.Width);
        int destHeight = (int)(0.5 * src.Height);
        
        using (Bitmap dest = new Bitmap(destWidth, destHeight))
        using (Graphics gDest = Graphics.FromImage(dest))
        {