adding a row into a table

gistfile1.js

      function addSource(){
          const count = document.querySelector("table#mainSources").querySelectorAll("tr").length;
          const newRow = document.querySelector("tr#tr-0").cloneNode(true);
          newRow.id = "tr-"+count;
          newRow.querySelectorAll("td").forEach(td => {
            const name = td.getAttribute("name");
            if (name == "alias" || name == "mID"){
              td.querySelector("label").innerHTML = td.querySelector("label").innerHTML.replace(":", " " + count + ":");
              td.querySelector("input").id = td.querySelector("input").getAttribute("id").replace("0",count);
              td.querySelector("input").value = "";
            }
          })
          document.querySelector("table#mainSources").appendChild(newRow);
      }