Looking for a "add input field" button function in my case

Looking for a "add input field" button function in my case

I'm looking for a way to have a button in my form that will add another
text input when clicked, similar to the attachments form in Yahoo Mail.
This way the user can have exactly as many input fields as they need.
Any ideas? Thanks, Luk
Here's my input field : (add.gif is the add.gif add icon for input field &
delete.gid which is remove the input field)
response.Write "<td align='left'><img src=""..\common_pic\add.gif""
border=0><input type='text' value='" & adoRecordset("production_unit") &
"'name='production_unit' size='10'><img src=""..\common_pic\delete.gif""
border=0></td>"