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);
}