<input name="receipt" id="receipt" type="checkbox" checked="checked" <php>/>
         <label><php></label>

document.getElementById('img').click = clickImg();

<script>

// Добавить обработчик событий
function addHandler(object, event, handler, useCapture) {
    if (object.addEventListener)
        object.addEventListener(event, handler, useCapture);
    else if (object.attachEvent)
        object.attachEvent('on' + event, handler);
    else object['on' + event] = handler;
}

// Убрать обработчик событий
function removeHandler(object, event, handler) {
    if (object.removeEventListener)
        object.removeEventListener(event, handler, false);
    else if (object.detachEvent)
        object.detachEvent('on' + event, handler);
}


</script>






<div id="test">Click me!</div>





<script>

var div = document.getElementById("test");

function test() {
      alert("One time!");
      removeHandler(div, "click", test);
}

addHandler(div, "click", test);

</script>

var doc_width = document.body.clientWidth;
var doc_height = document.body.clientHeight;