$(function() {

    $(".plus-button").live('click',function() {
        var $button = $(this);
        var oldValue = $button.parent().find("input.items-count").val();

        if ($button.text() == "+") {
            if (oldValue == '')
                oldValue = 0;
    	  var newVal = parseFloat(oldValue) + 1;
    	  // AJAX save would go here
    	} else {
    	  // Don't allow decrementing below zero
    	  if (parseFloat(oldValue) >= 2) {
    	      var newVal = parseFloat(oldValue) - 1;
    	      // AJAX save would go here
    	  }else
              var newVal = 1;
    	}
    	$button.parent().find("input.items-count").val(newVal);
    });

});