Javascript needed for finding a box in a html page then setting contents

Question

Can anyone show me how to get to a text edit box in a html page and set its value using Java script please?

Answer 1

<input type="textbox" id="ExampleTextBox" />

If you know the id of it:

document.getElementById(TEXTBOX_ID).value = YOUR_VALUE;

or in a function:

function chanageTextBoxValue(newValue)
{
   document.getElementById('ExampleTextBox').value = newValue;
}

Answer 2

Given a text box

<input type="text" id="MyInput">

You Javascript would look like:

document.getElementById("MyInput").value = "some value";

There will be other ways of doing this if you are using a JavaScript framework, for example in jquery, the following will suffice:

$("#MyInput").val("some value");

Answer 3

You can access it through your form:

document.myForm.firstName.value = "Hello World";

--

<form name="myForm">
  <input type="text" name="firstName" />
</form>