Element.implement({

shake : function(radius,duration){

radius = radius || 3;

duration = duration || 500;

duration = (duration/50).toInt() - 1;

var parent = this.getParent();

if(parent != $(document.body) && parent.getStyle('position')=='static'){

parent.setStyle('position','relative');

}

var position = this.getStyle('position');

if(position=='static'){

this.setStyle('position','relative');

position = 'relative';

}

if(Browser.Engine.trident){

parent.setStyle('height',parent.getStyle('height'));

}

var coords = this.getPosition(parent);

if(position == 'relative' && !Browser.Engine.presto){

coords.x -= parent.getStyle('paddingLeft').toInt();

coords.y -= parent.getStyle('paddingTop').toInt();

}

var morph = this.retrieve('morph');

if (morph){

morph.cancel();

var oldOptions = morph.options;

}

var morph = this.get('morph',{

duration:50,

link:'chain'

});

for(var i=0 ; i < duration ; i++){

morph.start({

top:coords.y+$random(-radius,radius),

left:coords.x+$random(-radius,radius)

});

}

morph.start({

top:coords.y,

left:coords.x

}).chain(function(){

if(oldOptions){

this.set('morph',oldOptions);

}

}.bind(this));

return this;

}

});