var xmlhttp = false; // IE Check bool

try { // Check for IE
  xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");// Javascript > 5
} catch (e) {
  try { 
    xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");// Older version of IE
  } catch (e) {
  xmlhttp = false;// Not using IE
  }
}

// Instantiate xmlhttp object if not IE
if(!xmlhttp && typeof (XMLHttpRequest != 'undefined')) {
  xmlhttp = new XMLHttpRequest();
}

function getData(phpFile, objID) {
  var obj = document.getElementById(objID);
  xmlhttp.open("GET", phpFile);
  xmlhttp.onreadystatechange = function() {
    if(xmlhttp.readyState == 4 && xmlhttp.status == 200) {
      obj.innerHTML = '';
      obj.innerHTML = "£" + xmlhttp.responseText;
    }
  }  
  xmlhttp.send(null);
}

function getPrice(productID, optionID, objID) {
  getData("action.php?view=product&action=getprice&product=" + productID + "&var_id=" + optionID, objID);
}