Bugfix_6

Problem with tutorial code: if we input 0, - it shows 2nd image, if 1, - first. There is no blending. And nothing strange, because for blending work, alpha should be at least 0.5 (default value). If we talking about blending, why user should choose between simple opening of two images? I propose, at least, change a little bit code for it work correct.
Plus: I add a source code from tutorial.