Transmission is slipping sometimes should i put transmission fluid in at 118k m

What is your question?

My transmission has been slipping on the occasion and with the 2001 model you do not have a dip stick to check your transmission levels, should i just poor some in and see if it helps or should I do a complete flush of the fluid?Also when trying to start the car i have to take the key out and put it back in and turn at the same time to get it to start, any suggestions and repair cost? Thanks in advanced What seems to make the problem better or worse? Nothing How long have you had this problem? Just got the car 3 days ago