Using buttons to check and uncheck checkboxes

I'm trying to write some code that uses buttons to check and uncheck certain checkboxes. I am stumped and all the code I have been finding is using for loops to check or uncheck all the boxes, when I just want to check or uncheck certain ones.

Here's an example of the type of function I'm trying to use:
function checkSome (form) {
document.myForm.list.one.checked = true;
document.myForm.list.two.checked = true;
document.myForm.list.three.checked = false;
}

And the button:
<input type="button" value="Option 1" onClick="checkSome(this.form)"/>

What was "list." in there for???

function checkSome (form) {
form.one.checked = true;
form.two.checked = true;
form.three.checked = false;
}

Assuming, that is, that you had
<input type="checkbox" name="one" />
<input type="checkbox" name="two" />
<input type="checkbox" name="three" />

The form I am using has several different inputs (not just the checkboxes) so I have
<input type="checkbox" name="list" value="one"/>
<input type="checkbox" name="list" value="two"/>
<input type="checkbox" name="list" value="three"/>

From my understanding I would have to have:
function checkSome (form) {
form.list.one.checked = true;
form.list.two.checked = true;
form.list.three.checked = false;
}
But it's still not working.

You are confusing the value of the checkbox with its name and index.

function checkSome (form) {
form.list[0].checked = true;
form.list[1].checked = true;
form.list[2].checked = false;
}

Remember that the index starts at 0 (the first checkbox in the group list is list[0]).


Obama can't be himself because of who he is. But now he is who he is. - Political commentator, BBC 2.