function preload(imgObj,imgSrc) {
	if (document.images) {
		eval(imgObj+' = new Image()')
		eval(imgObj+'.src = "'+imgSrc+'"')
	}
}
function changeImage(layer,imgName,imgObj) {
	if (document.images) {
		if (document.layers && layer!=null) eval('document.'+layer+'.document.images["'+imgName+'"].src = '+imgObj+'.src')
		else document.images[imgName].src = eval(imgObj+".src")
	}
}
function CheckBox(layer,imgName,trueValue,falseValue,defaultToTrue) {
	this.layer = layer
	this.imgName = imgName
	this.trueValue = trueValue
	this.falseValue = falseValue
	this.state = (defaultToTrue) ? 1 : 0
	this.value = (this.state) ? this.trueValue : this.falseValue
	this.change = CheckBoxChange
}
function CheckBoxChange() {
	this.state = (this.state) ? 0 : 1
	this.value = (this.state) ? this.trueValue : this.falseValue
	changeImage(this.layer,this.imgName,'checkbox'+this.state)
}