def colorize_syntax_error(self, msg, lineno, offset):
        text = self.editwin.text
        pos = "0.0 + %d lines + %d chars" % (lineno-1, offset-1)
        text.tag_add("ERROR", pos)
        char = text.get(pos)
        if char and char in IDENTCHARS:
            text.tag_add("ERROR", pos + " wordstart", pos)
        if '\n' == text.get(pos):   # error at line end
            text.mark_set("insert", pos)
        else:
            text.mark_set("insert", pos + "+1c")
        text.see(pos)