Bug 254900

Version:           unspecified (using KDE 4.5.1) 
OS:                Linux

Both when I open a plain text file or a lecture I made with ktouch, it allows characters that I can't type with the current layout into the lesson. This means that I can't finish the lesson because it is impossible to type the character.
Some of the characters that I have run across that caused problems:Mdash, smart quotes, copyright symbols, etc.

Reproducible: Always

Steps to Reproduce:
Make a plain text file with one of the following characters:Mdash, smart quotes, copyright symbols.
Open the plain text file (File > Open Plain Text File)
Try to finish the lesson, but notice that you can't since you get the special characters wrong and there is no way to correct them.

Make a lecture file with one of the following characters:Mdash, smart quotes, copyright symbols. (File > Edit Lecture. "Create a new lecture", etc). 
Open the plain text file (File > Open Lecture)
Try to finish the lesson, but notice that you can't since you get the special characters wrong and there is no way to correct them.

Actual Results:  
You cannot finish the lesson because it is impossible to type the characters.

Expected Results:  
Not 100% which one of these:
+ When opening lecture/plain text files, characters not on the keyboard should be removed.
+ Show how to enter the code for the character with the alt key (or whatever key is used).
+ Make lecture editor remove characters not on the keyboard layout.