dinamically showing datediff( in form

[mjunior]

Hi,

I have a datediff comparision value on my form. Since one of the dates inside the datediff is: now(), I'd like to know if there's a way to show the result dinamically (without reloading the page..).

I can't see how to do it from server side...It's possible to use js to fill the field or reload only the field value?

detail: I'll need to submit the current diftime value along the other input values on my form at the end of process..