The keys of the CONTROL group extend the functions of character input.
 (insert) key to change 
 between the modes insert and delete.
 (insert) key to change 
 between the modes insert and delete.In insert mode, the cursor appears in the input field.
 (backspace) key to 
 delete the character to the left of the cursor.
 (backspace) key to 
 delete the character to the left of the cursor. (delete) key to delete 
 the inversely displayed character (in overwrite mode).
 (delete) key to delete 
 the inversely displayed character (in overwrite mode).  (clear) key to delete 
 all characters.
 (clear) key to delete 
 all characters.