javascript calculations

[aweise]

How would I go about having three fields next to each other. The first one for adding quantity, the second for adding cost and then finally the third would show the result of the first two. When there are no values this field will show a zero.

How would I create this?

[moltar]

1. Create a form (

   calc

   ) with three input elements next to each other (

   qty, cost, total

   )
   
2. Write a function that will read data from

   qty

   and

   cost

   inputs
   
3. Add up the values
   
4. Write total to

   total

   .
   
5. Set

   onchange

   action calling the above function on qty and cost fields.
   
6. Optional: add a button (

   type="button"

   ) in the form and put

   onclick

   action on it calling the above function
   

You can get/set value of a field like this:

document.calc.[b]FIELD_NAME[/b].value

[aweise]

I'm a bit clueless on writing javascript functions. But I will try to go online and search this out given the steps you have outlined.

Thanks for your help.

[moltar]

Functions are pretty much like in other languages:

function calc() {
 ... does calculations ...
}