//global variables that can be used by ALL the function son this page.
var inputs;
/*var imgFalse = '/images/false.png';*/
var imgFalse = [];
imgFalse[0] = '/images/muziek_false.gif';
imgFalse[1] = '/images/theater_false.gif';
imgFalse[2] = '/images/dans_false.gif';
imgFalse[3] = '/images/beeldend_false.gif';
imgFalse[4] = '/images/literatuur_false.gif';
imgFalse[5] = '/images/erfgoed_false.gif';
imgFalse[6] = '/images/fotografie_false.gif';

/*var imgTrue = '/images/true.png';*/
var imgTrue = [];
imgTrue[0] = '/images/muziek_true.gif';
imgTrue[1] = '/images/theater_true.gif';
imgTrue[2] = '/images/dans_true.gif';
imgTrue[3] = '/images/beeldend_true.gif';
imgTrue[4] = '/images/literatuur_true.gif';
imgTrue[5] = '/images/erfgoed_true.gif';
imgTrue[6] = '/images/fotografie_true.gif';

//this function runs when the page is loaded, put all your other onload stuff in here too.
function init() {
    replaceChecks();
}

function replaceChecks() {
    
    //get all the input fields on the page
    inputs = document.getElementsByTagName('input');

    //cycle trough the input fields
    for(var i=0; i < inputs.length; i++) {

        //check if the input is a checkbox
        if(inputs[i].getAttribute('type') == 'checkbox') {
            
            //create a new image
            var img = document.createElement('img');
            
            //check if the checkbox is checked
            if(inputs[i].checked) {
                img.src = imgTrue[i];
            } else {
                img.src = imgFalse[i];
            }

            //set image ID and onclick action
            img.id = 'checkImage'+i;
            //set image
            img.onclick = new Function('checkChange('+i+')');
            //place image in front of the checkbox
            inputs[i].parentNode.insertBefore(img, inputs[i]);
            
            //hide the checkbox
            inputs[i].style.display='none';
        }
		
    }
}

//change the checkbox status and the replacement image
function checkChange(i) {

    if(inputs[i].checked) {
        inputs[i].checked = '';
        document.getElementById('checkImage'+i).src=imgFalse[i];
    } else {
        inputs[i].checked = 'checked';
        document.getElementById('checkImage'+i).src=imgTrue[i];
    }
}

window.onload = init;