Call JS function from outside of input tag?

[Abstract]

Hi Everyone,
I am working with an online form management system. I have tried to access Support for help, but I have not got a response from them. Throughout the years, the people at WebDesignForums.net have always been a big help, and I assume someone on this board can help me.

With that said, here is my issue:
I am using javascript to pre-populate a form on a field based on another field's value. The form management system does not allow me access the input tag and add the "onkeyup" function. Is there any way I can remotely attribute this function to the field within the javascript code instead of the input tag?

Here is the script I am using (I am pre-populating an age (ID: AGE) field based on the date of birth (ID: DOB) field someone fills out:

<script type="text/javascript">
function DOBcalc() {
  var DOBmdy = (document.getElementById('DOB').value).split('/');
  Bdate = new Date(DOBmdy[2],DOBmdy[0]-1,DOBmdy[1]);
  BDateArr = (''+Bdate).split(' ');
  document.getElementById('DOW').value = BDateArr[0];
  Cdate = new Date;
  CDateArr = (''+Cdate).split(" ");
  Age = CDateArr[3] - BDateArr[3];
  document.getElementById('AGE').value = Age;
}
</script>

Let me know if it is possible. Thanks!

[smoseley]

window.onload = function() {
document.getElementById('DOB').onblur = DOBcalc;
|

[Abstract]

window.onload = function() {
document.getElementById('DOB').onblur = DOBcalc;
|

Thanks for the quick response! I'm not too skilled in JS so forgive me if this is an elementary question, but I can add that within the script under the curly bracket but before the closing tag, right?

[smoseley]

Yup!

[Abstract]

Thank you for your help.

It seems like this form creator is quirkier than I would like it to be. It won't let me dynamically populate the field using the code above. My alternative would just be to execute the function once the submit button is hit and just have the field populate that way (the age is more for our reference anyway). How can I execute the function when the form is submitted outside of the submit tag?

[Abstract]

I've been going crazy trying to figure out why I couldn't get your suggestion above to work. Then I realized you accidentally put a | at the end instead of a }.

LOL. Thanks for your help.