function set()
{
	this.length = 0;

	this.add =		set_add;
	this.remove =	set_remove;
	this.find =		set_find;
}

function set_add(item)
{
	if (this.find(item) >= 0)
		return;

	this[this.length] = item;

	this.length++;
}

function set_remove(item)
{
	i = this.find(item)
	
	if (i >= 0)	
	{
		this.length--;
		this[i]=this[this.length];
	}
}

function set_find(item)
{	
	for (i=0; i<this.length; i++) //>
	{
		if (this[i]==item)
			return i;
	}
	
	return -1;
}