How do I determine if a checkbox is checked?

Question

For some reason, my form does not want to get the value of a checkbox... I am not sure if it is my coding or not, but when I try and alert() the value, I get

Answer 1

Place the var lfckv inside the function. When that line is executed, the body isn't parsed yet and the element "lifecheck" doesn't exist. This works perfectly fine:

function exefunction() {
  var lfckv = document.getElementById("lifecheck").checked;
  alert(lfckv);
}

Lives
Check value