Resizer = function(panelElId, handleElId, sGroup) {
    if (handleElId) {
        this.init(panelElId, sGroup);
        this.handleElId = handleElId;
        this.setHandleElId(handleElId);
    }
};

Resizer.prototype = new YAHOO.util.DragDrop();

Resizer.prototype.onMouseDown = function(e) {
    var panel = this.getEl();
    this.startWidth = panel.offsetWidth;
    this.startHeight = panel.offsetHeight;

    this.startPos = [YAHOO.util.Event.getPageX(e),
                     YAHOO.util.Event.getPageY(e)];
};

Resizer.prototype.onDrag = function(e) {
    var newPos = [YAHOO.util.Event.getPageX(e),
                  YAHOO.util.Event.getPageY(e)];

    var offsetX = newPos[0] - this.startPos[0];
    var offsetY = newPos[1] - this.startPos[1];

    var newWidth = Math.max(this.startWidth + offsetX, 10);
    var newHeight = Math.max(this.startHeight + offsetY, 10);

    var panel = this.getEl();
    panel.style.width = newWidth + "px";
    panel.style.height = newHeight + "px";
};