Well, it's too simple. I thought you said "like MS Paint" (actually you did!). However for your reason you should call PictureBox_Paint in Button_Click (be careful of parameters) and use e.Graphics.DrawRectangle(Pen pen, int x, int y, int width, int height) (+2 overload(s)) to draw a rectangle. Or you have something else to say? :^) While (true) { Human.isLearnable = true; }

dennycrane wrote: don´t I need a list to compare though? You already do. These 2 lines are string arrays (a kind of list): string[] correctlySpelledWords = { "foo", "bar", "bat", "baz" }; string[] studentSpelledWords = richTextBox1.Text.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries); One is a list of correctly spelled words, another is th elist of student-spelled words.

That just turns things around. Now everything is different.

static bool Compare(SortedList SL, SortedList SL2) { if(SL.Count != SL2.Count) return false; for(int i = 0 ; i < SL.Count ; i++) { if(SL[i] != SL2[i]) return false; } return true; Is that right?

Hi, seems to me you need to: - split both texts into words (split on spaces and puctuation); - match the words (resync when a word is missing in one of the texts); - count the differences (each pair of matching words that are not identical count as one mistake). Why match words: the sucker under test may connect two words, split a word in two, just forget one, etc. remaining problems: - punctuation: do you check those chars too? can you hear the difference between say a semi-colon and a period? - capitals: are the rules strict in your language? is it the same for the first letter following a semi-colon and a period? :) Luc Pattyn [Forum Guidelines] [My Articles] This month's tips: - before you ask a question here, search CodeProject, then Google; - the quality and detail of your question reflects on the effectiveness of the help you are likely to get; - use PRE tags to preserve formatting when showing multi-line code snippets.