var ISBNValidate = function(){
	var AnyISBNs = false;
	var objISBNs;
	
	for (var i = 0; i < 50; i++) {
		objISBNs = document.BuybackISBNForm.ISBNs[i];
		if (objISBNs && Trim(objISBNs.value) != '')
			AnyISBNs = true;
	}
	
	if (!AnyISBNs)
		alert('Please enter at least one ISBN.');
		
	return AnyISBNs;
}

var PricingValidate = function(){
	var AnySelectedProds = false;
	var ProdQty = 0;
	var SelProdBadQtyCnt = 0;
	
	if (document.BuybackPricingForm.ProdIDListSel) {
	   if (typeof document.BuybackPricingForm.ProdIDListSel.length != 'undefined') {
			for (var i = 0; i < document.BuybackPricingForm.ProdIDListSel.length; i++) {
				if (document.BuybackPricingForm.ProdIDListSel[i].checked==true){
					AnySelectedProds = true;
					ProdQty = eval('document.BuybackPricingForm.Qty' + document.BuybackPricingForm.ProdIDListSel[i].value).value;
					if (ProdQty == '' || IsNumeric(ProdQty)==false || ProdQty == 0)
						SelProdBadQtyCnt++;
				}
			}
	   } else {
		  AnySelectedProds = document.BuybackPricingForm.ProdIDListSel.checked;
		  if (AnySelectedProds){
				ProdQty = eval('document.BuybackPricingForm.Qty' + document.BuybackPricingForm.ProdIDListSel.value).value;
				if (ProdQty == '' || IsNumeric(ProdQty)==false || ProdQty == 0)
					SelProdBadQtyCnt++;
		  }
	   }
	}	
	
	if (!AnySelectedProds){
		alert('Please select at least one book to continue.');
		return false;
	} else { 
		if (SelProdBadQtyCnt > 0){
			alert('One or more quantities are missing or invalid.');
			return false;
		}
	}
		
	return true;
}