var currentslide;
var slidesmax;
currentslide=1;

function slidenext(){
	slidesmax=document.getElementById('amount_in_top').value;
	var slidename='slider_product'+currentslide;
	document.getElementById(slidename).style.display="none";
	if (currentslide==slidesmax) currentslide=1;
	else
	currentslide++;
	var nextslide="slider_product" + currentslide;
	document.getElementById(nextslide).style.display="block";
}

function slideprev(){
	slidesmax=document.getElementById('amount_in_top').value;
	var slidename='slider_product'+currentslide;
	document.getElementById(slidename).style.display="none";
	if (currentslide==1) currentslide=slidesmax;
	else
	currentslide--;
	var nextslide="slider_product" + currentslide;
	document.getElementById(nextslide).style.display="block";
}