Hi,
For example:
Go to your form->Advanced->more options->Scripts->
Initialization Script->Custom->Create code framework and try this:
function ff_comb_init()
{
setInterval(calc, 500);
} // ff_comb_init
function calc() {
ff_getElementByName("d").value=ff_getElementByName("a").value+ff_getElementByName("b").value+ff_getElementByName("c").value;
}Note:
comb is name of form. Please replace comb with your form name, and a,b,c,d is name for form element A,B,C,D. Please replace this with your name for A,B,C,D.
Let me know if you want this.
Regards,
Tihana
Autor del tema 
