I've been learning C and windows API for a month now, and I've got some problems creating a second MDI child window. I've attached the files.
The MDI children have their class registered in the "ChildClasses.h" file and created in the "CreateChildren.h" file. I call the latter from the "MedDiretas.h", on the "case IDOK".
Running the program, clicking on menu "Arquivo" > "Nova Medi