Javascript event that fires without user interaction?

Question

A textbox on my form may change depending on what\'s selected in various drop down lists.

Is there a way to call a javascript function when the textbox value changes? <

Answer 1

In web browsers, programmatic changes on a control won't trigger events on that control. You must instruct the code that changes the textbox value to trigger the onchange event. This is how you can do it in plain javascript:

var textbox = document.getElementById("boxId");
textbox.value = "Abc";
textbox.onchange();

Of course, using a library like jQuery makes it easier and more robust:

$("#boxId").val("Abc").change();