drag drop question - javascript error

good morning,

I searched but didn't anything that specifically matched this.

I have a page with 1 drag/drop question.

I'm dragging a text block onto one of three possible drop areas (1 correct, 2 incorrect).

When the page loads I get a javascript error in IE7 (yeah, I know).

line: 252

Char: 3

Error: Object doesn't support this property or method

Code:0

URL: ../trivantis-drag.js

When I look at trivantis-drag.js at the line indicated I see this:

248 for (var i = 0; i < totalDragItems; i++)

249 {

250 var elem = dragMgr.arrDragItems.lyr.objLyr.ele;

251 elem.addEventListener("touchstart", function(event){

252 event = event || window.event;

253 DragMouseDown.apply(dragMgr, [event.changedTouches[0].pageX, event.changedTouches[0].pageY, event]);

254 });

255

256 elem.addEventListener("touchmove", function(event){

257 event = event || window.event;

258 event.preventDefault();

259 DragMouseMove.apply(dragMgr, [event.changedTouches[0].pageX, event.changedTouches[0].pageY]);

260 });

261

262 elem.addEventListener("touchend", function(event){

263 DragMouseUp.apply(dragMgr);

264 });

Sometimes the drag/drop question works perfect (even with the error message)

Sometimes it acts like the drag text is simply straight text and won't drag. That is, i can use my house and highlight the text, but i can't move it.

Any suggestions?

thanks