How To Run An Event-triggered Function From Inside A HTML Tag?

when I call my "moveObject" function by an onMouseUp event handler like this:

<script>
document.onmouseup = function (e) {
moveObject(e,testTable);
};
</script>
everything works fine. But I would like to call that function not by clicking anywhere in the document, but by clicking on a table clell. I used this:

...<td onMouseUp="moveObject(e,testTable)">My text</td>...

This unfortunately doesn't work. Can You see the error??