Problem with adding just one link (href) on the page

Question

Hi,


I want to add only once the href, but it appears every time the automatic refresh is done Can anybody help me please?
Here is the code:
function exportCSV() {
  //download stuff
  var buffer = csvData.join("\n");
  var uri = "data:text/csv;charset=utf8," + encodeURIComponent(buffer);
  var fileName = "data.csv";
  var link = document.createElement("a");
  if (link.download !== undefined) { // feature detection
  // Browsers that support HTML5 download attribute
  link.setAttribute("href", uri);
  link.setAttribute("download", fileName);
  }
  else if (navigator.msSaveBlob) { // IE 10+
  link.addEventListener("click", function (event) {
  var blob = new Blob([buffer], {
  "type": "text/csv;charset=utf-8;"
  });
  navigator.msSaveBlob(blob, fileName);
  }, false);
  }
  else {
  // it needs to implement server side export
  link.setAttribute("href", "http://www.example.com/export");
  }
  link.innerHTML = "Export to CSV";
 
  document.body.appendChild(link);
 
  }
Thanks