My code has an error and I can not solve. line 110 is in bold. note: notice that both functions are fine!
val drawImage :
  width:int * height:int ->
    space:float32 -> coreDrawingFunc:(Graphics -> unit) -> Bitmap

>

val drawElements : elements:seq<ScreenElement> -> gr:Graphics -> unit

>>>>>>>>>>>>>>>>>>>>>

open System.Windows.Forms

let fntText = new Font("Calibri", 12.0f)
let fntHead = new Font("Calibri", 15.0f)

let parts =
  [ TextElement
     ({ Text = "Functional Programming for the Real World"; Font = fntHead },
      { Left = 5.0f; Top = 0.0f; Width = 410.0f; Height = 30.0f });
    ImageElement
     ("C:\\Tomas\\Writing\\Functional\\Petricek.jpg",
      { Left = 120.0f; Top = 30.0f; Width = 150.0f; Height = 200.0f });
    TextElement
     ({ Text = "In this book, we'll introduce you to the essential "+
               "concepts of functional programming, but thanks to the .NET "+
               "Framework, we won't be limited to theoretical examples. We'll "+
               "use many of the rich .NET libraries to show how functional "+
               "programming can be used in the real-world."; Font = fntText },
     { Left = 10.0f; Top = 230.0f; Width = 400.0f; Height = 400.0f }) ]

let main = new Form(Text = "Document", ClientSize=Size(450, 400))
main.BackgroundImage <- drawImage (450, 400) 20.0f (drawElements parts)
main.Show()

I ve made some adjustments and Now the error msg is this: As I understood the text function is a list and the drawElements is waiting for a seq... But I donot know how to handle this..

Program.fs(120,66): error FS0001: The type 'ScreenElement list' is not compatible with the type 'seq<ScreenElement>'

The original message indicated that there is no valid image file at the supplied path.

Normally it should be possible to use a list where a seq is expected.  If you've changed some things and then reevaluated them in FSI, then it's possible that you've redefined the ScreenElement type, so what the error message really means is something more like "The type '{old}ScreenElement list` is not compatible with the type `seq<{new}ScreenElement>`.  If that's the case, then try reevaluating everything so that it's all defined in terms of the same version of the type.

The original message indicated that there is no valid image file at the supplied path.

Normally it should be possible to use a list where a seq is expected.  If you've changed some things and then reevaluated them in FSI, then it's possible that you've redefined the ScreenElement type, so what the error message really means is something more like "The type '{old}ScreenElement list` is not compatible with the type `seq<{new}ScreenElement>`.  If that's the case, then try reevaluating everything so that it's all defined in terms of the same version of the type.