function afterLoad() {
    replaceElements(document.getElementsByTagName("span"), "&font=Calibri&size=16&style=bold&color=bc1d8d");
}

function replaceElements(elements, addQueryString) {
    var idx
    for (idx = 0; idx < elements.length; idx++) {
		if (elements[idx].className == "image-header") {
			replaceElement(elements[idx], addQueryString);
		}
    }
}

function replaceElement(element, addQueryString) {
    var txt;
    if (typeof(element.innerText) === 'undefined') {
        txt = element.textContent;
    } else {
        txt = element.innerText;
    }
    var imgE = document.createElement("img");
    imgE.style.display = 'none';
    imgE.src = 'https://imageheader.chatfone.nl/imageGenerator.aspx?text=' + txt + addQueryString; // escape() ?
    imgE.onload = function() {
        imgE.style.display = "";
        var idx;
        for (idx = element.childNodes.length - 1; idx >= 0; idx--) {    
            if (element.childNodes[idx] !== imgE) {
                element.removeChild(element.childNodes[idx]);
            } 
        }
    };
    
    element.appendChild(imgE);
    
}