can this be done ???

hi,
i have made a calculator with various input fields. What i would like to happen is that when a user clicks on a field an explanatory note appears on the right hand side (i.e. the "Notes" section) specific to the field the user has selected.

www.finser.com.au/calcs/retirement_a.html

N.B. There aren't any input fields in the above link yet

Cheers

<input type="text" name="txt1" title="This is the description for txt1" onfocus="document.getElementById('notes').innerHTML=this.title" />
<input type="text" name="txt2" title="This is the description for txt2" onfocus="document.getElementById('notes').innerHTML=this.title" />
<input type="text" name="txt3" title="This is the description for txt3" onfocus="document.getElementById('notes').innerHTML=this.title" />
...
<div id="notes"></div>

I put the explanatory notes in the title attribute so that it shows as a tooltip when the user mouses over the field.