How do i retrieve data after tabing out of field without submiting

[thepreacher]

I am developing a webpage with PHP that interacts with mysql. I have a form with fields that accept input. There are some fields that after data has been entered, and i tab out of, I want to be able to retrive the data and use it to query the database so as to porpulate other fields in the same form without submiting.

For example, i enter an account number amd after i tab out of it, i can use that data to query the database to get the content for the next field.

thanks a lot.

[cheerio]

AJAX. Just get the prototype library and use onchange="" with Ajax.Updater