function $(control_id){
	return document.getElementById(control_id);
}

function preloadImages() {
	var d=document;
	if(d.images){
		if(!d._pImgs)
			d._pImgs=new Array();
		var i,j=d._pImgs.length,a=preloadImages.arguments;
		for(i=0; i<a.length; i++){
			if (a[i].indexOf("#")!=0){
				d._pImgs[j]=new Image;
				d._pImgs[j++].src=a[i];
			}
		}
	}
}

function TreeStatebutton_Initialize(control_id){
	var control = $(control_id);
	var src = control.src;
	control.src_off = src.replace(/_(off|on)/, '_off');
	control.src_over = src.replace(/_(off|on)/, '_over');
	control.src_on = src.replace(/_(off|on)/, '_on');
	preloadImages(control.src_off, control.src_over, control.src_on);

	control.onmouseover = function(){
		this.orgsrc = this.src;
		this.src = this.src_over;
	};

	control.onmouseout = function(){
		this.src = this.orgsrc;
	};
}