function dr_getElem(type, id)
{
	var elem = document.getElementById(id);
	if (typeof elem == "undefined") {
		alert("missing " + type + " element: " + id);
		return null;
	} else {
		return elem;
	}
}

function dr_setText(e, s) {
	if (e.firstChild) e.firstChild.nodeValue = s;
	else e.appendChild(document.createTextNode(s));
}

function dr_setPlate(s) {
	var small_plate = dr_getElem('small plate', 'PlateBox');
	var big_plate = dr_getElem('big plate', 'largePlateLetters');
	
	dr_setText(small_plate, s);
	dr_setLargePlate(s);
	//alert(small_plate.firstChild.nodeValue);
}

function dr_setLargePlate(s) {
	//render this string on the large plate image
	var l = s.length;
	var prespaces = 4-parseInt(l/2); //truncated upwards

	//right, we can do the loop
	var i = 0;
	while (true) {
		if (i > 7) break;
		else if (i < prespaces) dr_setLargePlateLetter(i, "-");
		else if (i >= prespaces + l) dr_setLargePlateLetter(i, "-");
		else dr_setLargePlateLetter(i, s.charAt(i-prespaces));
		
		i += 1;
	}
}

function dr_setLargePlateLetter(i, c) {
	// handle space
	if (c == ' ') c = '-';

	var e = dr_getElem('letter', "lp_0" + i);

	// create new image element
	var imgNew = document.createElement('img');
	
	// give it an image
	// here I use the src of the icon just for convenience
	// you'd want to somehow determine the src of your desired image
	imgNew.src = "images/chars/" + c + ".gif";
	
	// give it an id
	imgNew.id = "lp_0" + i;
	//imgNew.setAttribute('height', '64');
	//imgNew.setAttribute('width', '*');
	
	// replace image
	var divParent = e.parentNode;
	divParent.replaceChild(imgNew, e);
}