Error: Unable to load dll (coredll.dll) (.net cf)

[Shreeram Natarajan]

Hi,

I have created a custom control derived from Textbox control for use in
Smart Phone Applications.
I have added the following declarations to invoke the dll functions from
coredll.dll to set the input mode of the
control to number mode.

[DllImport("coredll.dll", EntryPoint="GetCapture")]
private static extern IntPtr GetCapture();

[DllImport("coredll.dll", EntryPoint="GetWindow")]
private static extern IntPtr GetWindow(IntPtr handleWindow, int cmd);

[DllImport("Coredll.dll", EntryPoint="SendMessageW")]
private static extern uint SendMessage(IntPtr hWnd, uint msg, uint wParam,
uint lParam);

I have also created an Assembly for design time which will be used to add
the control to the Toolbox of VS.NET
The problem is whenever I try to create an instance of the control on the
form i get the following exception:

Unable to load dll (coredll.dll)

PLEASE ADVICE

Thanks
Shreeram