Can't set a value in a web form using "value='foo'", but entering the value manually is OK?-PHP Chinese Network Q&A

I tried using a similar method to set the values of several fields in the web form

document.getElementsByName('form[493202]')[0].value="Foo"

If I do this in the browser console, the field will be updated, but if I then manually click on the field, it will revert to the old value. The old values were entered manually by me.

This is a weird thing - if I enter a value manually, everything works as expected, including submitting the form, but if I enter the value using JS and then submit the form, I get a complaint that the field is empty (a Kind of a "compromise" between these results if I first enter the values manually and then change the values using JS. If I then click "Submit" the values revert to what I entered manually.), although from Visually, the fields are not empty - but when I click Submit, the fields are cleared (manually entered values remain after clicking Submit).

How is this going? How do I enter a value that this form "accepts" using JS?

Some HTML in the form, "Title", and this specific field:

     Name

function myFunction() { var field = document.getElementsByName('form[493202]')[0]; field.value = "Foo" // Trigger the oninput event var inputEvent = new Event('input'); field.dispatchEvent(inputEvent); // Trigger the onchange event var changeEvent = new Event('change'); field.dispatchEvent(changeEvent); }