function checknumber(number)
{
if (!isNumber(number.value) || isNaN(number.value))
  {
  alert('Not a valid number: ' + number.value);
  number.value = 0;
  number.focus();
  number.select();
  return false;
  }
return true;
}

function isPositiveNumber(number)
{
if (number.value.length==0) return true;
if (!checknumber(number)) return false;

if((number.value * 1) < 0)
  {
  alert('You must use a positive number: ' + number.value);
  number.value = 0;
  number.focus();
  number.select();
  return false;
  }
return true;
}

function checkqty(number, minqty, currentqty)
{

if (number.value.length > 0)
  {
  if (currentqty + '' == 'undefined')
    {
    currentqty = minqty;
    }
  if (number.value != '0')
    {
    if (isPositiveNumber(number))
      {
      return true;
      }
    else
      {
      number.value = currentqty;
      number.focus();
      number.select();
      return false;
      }
    }
  }

if (number.value * 1 < minqty)
  {
  alert('You must supply a quantity greater than ' + (minqty - 1));
  number.value = '';
  number.focus();
  number.select();
  return false;
  }
return true;
}

function showlargephoto(photoname, itemname)
{
var photowindow=window.open('details.asp?' + photoname + '&' + escape(itemname),'photowindow','toolbars=no,scrollbars=yes,height=460,width=620,resizable=yes');
photowindow.focus();
}

function isNumber(onestring)
{
var digit='-0123456789';
if (onestring.length==0) return false;
for (var oi=0;oi<onestring.length;oi++)
  {
  var onechar=onestring.charAt(oi);
  if (digit.indexOf(onechar)==-1) return false;
  }
return true;
}

function mouseover(status, button)
{
var buttonname = button.id;
buttonname = buttonname.replace('button', '');
window.status=status;
button.src = 'images/buttons/b-' + buttonname + 'over.gif';
return true;
}

function mouseout(button)
{
var buttonname = button.id;
buttonname = buttonname.replace('button', '');
window.status='';
button.src = 'images/buttons/b-' + buttonname + '.gif';
return true;
}