function setCompare(e)  {
  var numCompare = document.getElementById("numCompare");

  if(e.checked == true)  {
    if(parseInt(numCompare.value) < 4)  {
      numCompare.value = parseInt(numCompare.value) + 1;
    }
    else  {
      e.checked = false;
    }
  }
  else  {
    numCompare.value = parseInt(numCompare.value) - 1;
  }
}

function comparePizza()  {
  var i = 0;
  var k = 0;
  var e;
  var request = "";

  while(e = document.getElementById("compare" + i))  {
    if(e.checked)  {
      if(request != "")  {
        request = request + "&";
       }
       request = request + "compare" + k + "=" + e.value;
       k++;
    }
    i++;
  }

  if(request != "")  {
    PopUpWindow("compare.php?" + request, (k * 305), "525", "compare", 0);
  }
  else  {
    alert("You must enter a pizza to compare");
  }
}