Saving form input fields to MySQL br clicking on a button

Hi, I have a form where the user enters some information. For a particular section of the form, I'd like the user to be able to save what he/she entered so that the next time they feel out the form, they can recall without the need to retype. This is not for the entire form but only for a few input text fields. I created a button called "Memorize" but how do I have the page save the values to my MySQL database when the user clicks on the button. I understand that I can only use JavaScript to trap the "OnClick()" function and not PHP but I cannot use JavaScript to write to a MySQL table. I do not want to submit as that would reload the form and the user would lose other changes to other fields. Any idea? Don