Call Javascript function only when checkbox is NOT checked

Question

I'm trying to figure out how to call a Javascript function only when a checkbox is NOT checked.

Here is my checkbox:

<input type="checkbox" id="icd" name="icd" value="icd" />

Here is the name of the function:

planhide();

Answer 1

document.getElementById('icd').onchange = function() {
    if ( document.getElementById('icd').checked === false ) {
        planhide();
    }
};​

Answer 2

Include onchange option in the input tag and then add an intermediate function that checks and calls planhide() accordingly as follows:

<input type="checkbox" id="icd" name="icd" value="icd" onchange=check()/>

Then define the check() to do check the state and call the function as follows:

function check()
{
if(document.getElementById("icd").checked==false)
planhide();
}

Also instead of onchange you can also use onclick on the submit button option to call the check() function as like follows:

<input type="button" onclick=check()/>