Problems with MessageBox
<p>I have some code for a MessageBox, but I get a red line below the code and also in the beginning of the class at using System.Windows.Forms!?</p>

<p>Isn't it enough to add the using System.Windows.Forms to show MessageBoxes? Or could I have missed something else? Hints are preciated! Thanks! </p>

<p>EDIT:</p>

<p>The error message:
Error   1   The type or namespace name 'Windows' does not exist in the namespace 'System' (are you missing an assembly reference?)</p>
