function do_compare(comp_path)
{

   var comp = figure_out_all_prods_checked();

        if (4 < comp.length) {
                if (! (confirm('Only four products may be compared at one time. You currently have ' + comp.length + ' selected. Select OK to compare the first four products or Cancel to modify your selections.'))) {
                        return;
                }
        }


        if(comp.length < 2)
        {
                window.alert("Error: You must check 2 or more products to compare.");

        }  else {
		for (i=0;i<comp.length;i++) {
			comp[i] = "prodid=" + comp[i];
		}
                var str = comp.join('&');
                set_redirect(comp_path + "?" + str);
        }
}

function figure_out_all_prods_checked()
{
  var items = document.getElementsByName('compare');

  var comp = new Array();

  var j = 0;

  var old = document.getElementsByName('old_compare');
  for (i = 0; i < old.length; i++)
  {
          if (old[i].value) {
                  comp[j] = old[i].value;
                  j++;
          }
  }

  for(i=0; i < items.length; i++)
  {
    if(items[i].checked == true)
    {
      comp[j] = items[i].value;
      j++;
    }
  }
  return comp;
}

function clear_compare()
{

        var items = document.getElementsByName('compare');

        var old_items = document.getElementsByName('old_compare');

        for(i=0; i < old_items.length; i++)
        {
                old_items[i].value = '';
        }

        for(i=0; i < items.length; i++)
        {
                items[i].checked = false;
        }
}


function add_multiple_products()
{
	var multiple_add_checkboxes = document.getElementsByName('multiple_add_products');
	var none_chosen = true;
	for(var i=0;i<multiple_add_checkboxes.length;i++)
	{
		if(multiple_add_checkboxes[i].checked) {
			none_chosen = false;
			break;
		}
	}
	if(none_chosen)
		alert("Please choose at least 1 product to add");
	else 
			document.copage.submit();
}

function remove_product_from_comparison(prodid)
{
	var reg = new RegExp(prodid);
	var current_products = document.getElementById("prodid").value;
	document.getElementById("prodid").value = current_products.replace(prodid,"");
	document.copage.submit_name.value="remove";
	document.copage.submit();
}