forced line

I am storing the contents of a large input textfield into a mysql database. Problem is, when you force a line in the textfield, and save it it works. However the next time you save it, it adds another forced line. You save again and it will create another forced line. Is there comething I can do to prevent this?... eg... if when they save the text field... If I see a forced line, I can replace it with the flash term for a forced line, and save that in the database without the forced line but with the flash syntax for a forced line. Then when it comes to displaying the flash again it will read the flash syntax and display a forced line... get it????
thanks to any responders. J