Ok, thanks. I've looked through some of these tutorials and they look good for starting with jQuery so I'll work my way through some.
In the meantime if anyone knows of an example or tutorial that is close to what I'm try to achieve I'd be grateful if they could share.
I wouldn't have thought it would be too complicated to set a PHP session variable to the contents of a text form field as a user types in it - I thought I'd find an example of this but after lots of searching I've failed to find an easy way to do it. Any suggestions gladly received. Thanks