Default Choices in Dropdowns from Lookup Table

[roattw]

This has been asked before but the answer didnt work.  I have a Lookup table being called in a Datapage.  I want one of the table choices to be the default.  It work fine using Custon Lookup table and not using the table.  Previous posts said add this to footer:

<script type="text/javascript">
function f_default(){
document.getElementById("FieldName").value = "TheDefualtVaule";
}
window.onload = f_default;
</script>

I have done this, referencing the correct field name and value but it doesn't work.  Thoughts?

Thanks as always.

[Vitalikssssss]

Hi roattw,

What kind of datapage do you use and what kind of form element have you assigned to the field in which you would like to display default value?

This code works fine for submission form with default value assigned to a dropdown. 

<script type="text/javascript">
function f_default(){
document.getElementById("InsertRecordField_name").value = "Default";
}

document.addEventListener('DataPageReady', function (event) {
f_default();
       
});
</script>

Hope this helps.