Setting default values

In some cases, the selection or input of a certain value in your form should determine the default value for another field. Consider an extension of the example described in Disabling fields, in which a selection in a picklist named Membership Type determines the default value for another field named Membership Fee.

Follow these steps to create the logic that sets the value of a field based on the user's selection in another field:

Create a picklist named Membership Type with three values. Each of the values must have an integration code as shown below:

Add a script component to the page:

<script>
  function cust_membFee() {
  with (document.theForm) {
  var code = membership_type.options[
  membership_type.selectedIndex].getAttribute('code');
  if (code=='A')
  membership_fee.value=1000;
  else if (code=='C')
  membership_fee.value=500;
  else if (code=='S')
  membership_fee.value=200;
  else 
  membership_fee.value='';
  }
 }
 </script>

Add the following code to the onchange event handling code for the Membership Type picklist:
```
   if (typeof cust_membFee == 'function') cust_membFee();
```
Now, when the Membership Type option is selected and the Membership Fee box is empty, this box will be prepopulated with a new value depending on the selection.