MyProjectElement File1 = this.Project.Elements[0];
MyProjectElement File2 = this.Project.Elements[1];
MyProject my1 = (MyProject)File1;
MyProject my2 = (MyProject)File2;

PageCount_F1 = my1.PageCount;
PageCount_F2 = my2.PageCount;

if(PageCount_F1 != PageCount_F2) {
	MessageBox.Show("The 2 files need to have the same file length", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
} else {
	my1.IncludeAllPages = false;
	my2.IncludeAllPages = false;

	for(int i = 1; i <= PageCount_F1; i++) {
		StringBuilder value1 = new StringBuilder();
		StringBuilder value2 = new StringBuilder();
		value1.Append(i.ToString());
		value2.Append((PageCount_F2 - i + 1).ToString());
		MyProject my1new = new MyProject();
		MyProject my2new = new MyProject();
		my1new.Pages = value1.ToString();
		my2new.Pages = value2.ToString();
		my1.Pages = my1new.Pages;
		my2.Pages = my2new.Pages;

		this.Project.Elements.Add((MyProjectElement)my1);
		this.Project.Elements.Add((MyProjectElement)my2);

		((MyProject)this.Project.Elements[1]).Pages.Remove(0);
		((MyProject)this.Project.Elements[i]).Pages.Remove(0);
		((MyProject)this.Project.Elements[1]).Pages = "1";
		((MyProject)this.Project.Elements[PageCount_F2 - i + 1]).Pages = (PageCount_F2 - i + 1).ToString();

		((MyProject)this.Project.Elements[i-1]).Pages.Remove(0);
		((MyProject)this.Project.Elements[i]).Pages.Remove(0);
		((MyProject)this.Project.Elements[i - 1]).Pages = i.ToString();
		((MyProject)this.Project.Elements[i]).Pages = (PageCount_F2 - i + 1).ToString();
	}
}