function verifyformAddToCart()
{
var error="";
s=new String();
s=document.add2.quantity.value;
if(s=="") error+="The quantity field is empty!\n";
if ((s.indexOf(",")!=-1) || (s.indexOf(".")!=-1) ) error+="You have to enter a number without decimals!\n";
if (s == '0') error+="You have to enter a number different of 0 !\n";
if (error!="") alert(error);
return error=="";
}