function  change_product(prot_2){
    for(var i=1;i<=3;i++){
        if(i==prot_2){
            document.getElementById("product_item"+i).className="product_class"+i;
           document.getElementById("product_tab"+i).style.display="";
		   document.getElementById("product_tu"+i).style.display="none";
        }
        else{
            document.getElementById("product_item"+i).className="";
            document.getElementById("product_tab"+i).style.display="none";
			document.getElementById("product_tu"+i).style.display="";
        }
    }
}


function changeFontZise(size)
{
	var i=0;
			//c.style.fontSize = "18px"
	var c = document.getElementById("content")
	//for(i=0;i<c.childNodes.length;i++)
		if(size == "big")
			c.style.fontSize = "18px";
		else if(size == "mid")
			c.style.fontSize = "16px";
		else if(size == "small")
			c.style.fontSize = "12px";
	//alert(c.childNodes[i].style.fontSize);
}