.cs files not showing on TGB!

hi, I recently got TGB.I've been following tutorials on writing behaviors and I wrote one today using the Notepad and I saved it as a .cs file , then I put it on my game's behavior folder and reloaded the project but when I go to the behaviors list on TGB ,after clicking on the object I want to use it on,the behavior just doesn't show up,it doesn't appear.I downloaded a sample of a .cs file and put it into the same behaviors folder ,did the same thing I did before and it showed.I don't know why it's not reading the .cs files that I write on my computer.Please I need help, I've tried everything.

~Anilu~