<script language="JavaScript">
var items=0;
function Add()
{
items++;
var new_block = "<div id=\"form_" + items +"\"><input type=\"text\" name=\"cargo_"+items+"\"  size=\"45\">
<a href=\"javascript: Add()\" id=\"add\">add</a>
<a href=\"javascript: Remove('form_"+items+"')\">del</a></div>
<div id=\"show_new\">&</div>";
document.getElementById("show_new").InnerHTML=new_block;
}

function Remove(element_id){
 var div=document.getElementById(element_id);
 div.outerHTML = '';
}
</script>

<form id="frm">
<div id="form_0">
<input type="text"  name="cargo_0"  size="45">
<a href="javascript: Add()" id="add">add</a>
</div>
<div id="show_new">&</div>
</form>