How focus to IE window by API

Hello every one
I create a add-on for IE7.  The focus of my add-on is auto print html page without print dialog
I have 1 problem please help me. This is my code:

class Win32Lib
        [DllImport("User32.dll", CharSet = CharSet.Auto)]
        public static extern Int32 FindWindow(string lpClassName, string lpWindowName);
        [DllImport("User32.dll", CharSet = CharSet.Auto)]
        public static extern Int32 PostMessageA(Int32 hwnd, Int32 wMsg, Int32 wParam, Int32 lParam);

        [DllImport("User32.dll", CharSet = CharSet.Auto)]
        public static extern Int32 BringWindowToTop(Int32 hwnd);

        [DllImport("User32.dll", CharSet = CharSet.Auto)]
        public static extern Int32 SetForegroundWindow(Int32 hwnd);
        [DllImport("User32.dll", CharSet = CharSet.Auto)]
        public static extern Int32 SetActiveWindow(Int32 hwnd);

file PrintTool.cs
public class Download : IDownload
        /// <summary>
        /// COM exposed Method.
        /// </summary>
        public const Int32 BM_CLICK = 0xF5;
        public const Int32 VK_MENU = 0x12;
        public const Int32 VK_F = 0x46;
        public const Int32 VK_P = 0x50;
        public void InvokeMethod(string inputTest)
            Int32 hMain, sButton;
            hMain = Win32Lib.FindWindow("IEFrame", "TestPrint - Windows Internet Explorer");            
            if (hMain != 0)
                //hMain = Win32Lib.FindWindowEx(hMain, 0, "TabWindowClass", null);
               // hMain = Win32Lib.FindWindowEx(hMain, 0, "Shell DocObject View", null);
                //hMain = Win32Lib.FindWindowEx(hMain, 0, "Internet Explorer_Server", null);
//                Win32Lib.SetActiveWindow(hMain);
                hMain = Win32Lib.FindWindow("#32770", "Print");
                sButton = Win32Lib.FindWindowEx(hMain, 0, "Button", "&Print");
               Win32Lib.PostMessageA(sButton, BM_CLICK, 0, 0);

My add-on can run correct when i call another page, example click a button on Page A print Page B
but it can't run correct when print itself , example click a button on Page A and print Page A

Please help me, thank you
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

How does it fail?
globallaboAuthor Commented:
Thank you for your comment.
The function not auto print for me ( print without dialog). I call this function via javascript
But there is a strange. When i call this function, then i click to URL bar. The function run correct :(. I think there is some thing wrong with SetForegroundWindow API window i use
globallaboAuthor Commented:
No expert can help me :(( . Please.
I am interested if you found the solution or not.
Also I am trying to find url of running IE 7 using similar methods, but failed to retrieve it. I am wondering if you have any suggestion.

globallaboAuthor Commented:
Thank you  for all expert who care my problem. Now, i found another solution to send message to IE
I change from SendWait api to keybd_event api. It ok for me now. thank again

Win32Lib.keybd_event(VK_LCONTROL, 0, 0, 0);
Win32Lib.keybd_event(VK_P, 0, 0, 0);

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Web Browsers

From novice to tech pro — start learning today.