Input incremantation

increment.js

$(".diet_counter p").on("click", function() {

    var $button = $(this);
    var $input = $(".diet_counter input");
    var oldValue = $(".diet_counter input").val();

    if ($button.text() == "+") {
      var newVal = parseFloat(oldValue) + 1;
    } 
    else {

      if (oldValue > 1) {
        var newVal = parseFloat(oldValue) - 1;
      } 
      else {
        newVal = 1;
      }
    }
    $input.val(newVal);
});