// if not a number, toss an alert and reset the field to 0
function validateInt(field,orig)
{
  if(isNaN(field.value))
  {
    alert("That is not a valid quantity.")
    field.value = orig;
    return false;
  }
}

// if blank, toss an alert
function validateNotBlank(field,desc){
  if(field.value == "")
  {
    alert("The " + desc + " can not be blank.");
    return false;
  }
}