Würde ich so machen:
Code
<div id="container"></div> <button id="newteam">Weiteres Team hinzufügen</button>
<script>
var nr = 0;
var html = '<fieldset>\
<legend>Team 1</legend>\
<label for="teamid">Team-ID:</label>\
<input type="number" maxlength="10">\
<label for="already_purchased_players">Transferübersicht der letzten 5 Saisons vor dem Zeitraum:</label>\
<textarea name="already_purchased_players" cols="80" rows="20" id="already_purchased_players"></textarea>\
<label for="transferuebersicht">Transferübersicht:</label>\
<textarea name="transferuebersicht" cols="80" rows="20" id="transferuebersicht"></textarea>\
</fieldset>';
document.getElementById("newteam").addEventListener("click", function () {
nr++;
var chtml = html.replace("<legend>Team 1</legend>", "<legend>Team " + nr + "</legend>")
document.getElementById("container").innerHTML += chtml;
}); </script>
Alles anzeigen