There are many problems with the code.
Firstly, you defined the function allowDrop but then you reference the function allowdrop (lowercase) which is not defined, so it is not executing that function at all.
Secondly, your drag-and-drop functions do not do anything. To drag and drop you need to move the element to the mouse's position.
To fix this code would require many changes.
Consider reading about how to drag-and-drop in HTML here: