Javascript-форум - Добавление строки в таблицу + условие

Добрый день, есть вот такой код привожу вместе с css:

<!DOCTYPE HTML html public "-//W3C//DTD HTML 5 Transitional//EN">
<html>
	<head>
		<title>form</title>
		<meta charset="utf-8">
		<link rel="stylesheet" type="text/css" href="class1.css">
		<style type="text/css">
		.base{height: 20px;
width:50px;
border: 1px solid black;
text-align: left;}
.s1{font-size: 80%}
select[name="group"]{height: 20px;
width:150px;
text-align: left;}
.add{height: 20px;
width:50px;
text-align: center;
border-right: 1px solid black;}
.ext{height: 20px;
width:50px;
text-align: left;
border-right: 1px solid black;
border-left: 1px solid black;}
input[type="text"]{width:80px;}
select[name="trainer"]{height: 20px;
width:100px;
text-align: left;}
select[name="weekday"]{height: 20px;
width:80px;
text-align: left;}
select[name="classroom"]{height: 20px;
width:60px;
text-align: center;}
select[name="from"]{height: 20px;
width:50px;}
select[name="till"]{height: 20px;
width:50px;}
.fbase{height: 20px;
width:50px;}
.end{height: 20px;
width:50px;
border-right: 1px solid black;
border-bottom: 1px solid black;}
.ext1{height: 20px;
width:50px;
text-align: right;
border-right: 1px solid black;
border-left: 1px solid black;
border-bottom: 1px solid black;}
.fbase{height: 20px;
width:50px;}

		</style>
	</head>
	<body>
		<table cellSpacing='0' cellPadding='0'>
			<thead>
				<tr><th class="base" colspan="10" rowspan="2"><span class="s1">Group  <select name="group"></select></span><br><span class="s1"><input type="checkbox">  Separate data for each Module</span></th></tr>
				<tr></tr>
			</thead>
			<tbody>
				<tr>
					<td class="base" colspan="3" rowspan="3">
						<span class="s1">jd01</span><br>
						<span class="s1">jd02</span><br>
						<span class="s1">jd03</span>
					</td>
					<td class="base" colspan="7">
						<span class="s1">Intramural classes</span>
					</td>
				</tr>
				<tr>
					<td class="add" colspan="2" rowspan="2">
						<span class="s1">Weekdays</span>
					</td>
					<td class="add" colspan="3" rowspan="2">
						<span class="s1">Timing</span>
					</td>
					<td class="add" rowspan="2">
						<span class="s1">Classroom</span>
					</td>
					<td class="add" rowspan="2">
						<span class="s1">Academic hours</span>
					</td>
				</tr>
				<tr></tr>
				<tr>
					<td class="ext" colspan="3"><span class="s1">Trainer  <select  name="trainer"></select></span></td>
					<td class="add" colspan="2">
						<span><select name="weekday"></select></span>
					</td>
					<td class="add" colspan="3">
						<span class="s1">from <select name="from"></select> till <select name="till"></select></span>
					</td>
					<td class="add">
						<span class="s1"><select name="classroom"></select></span>
					</td>
					<td class="add">
						<span></span>
					</td>
				</tr>
				<tr>
					<td class="ext" colspan="3"><span class="s1">Start date <input  type="text"  name="date" value="" pattern="" placeholder="dd.mm.yyyy" required></span></td>
					<td class="add" colspan="2">
					</td>
					<td class="add" colspan="3">
					</td>
					<td class="add">
					</td>
					<td class="add">
					</td>
				</tr>
				<tr>
					<td class="ext1" colspan="3"><span class="s1" ><input type="button" value="Submit"  class="btn btn-success"></span></td>
					<td class="end" colspan="2">
						<span class="s1"><a href="#">+Add weekdays</a></span>
					</td>
					<td class="end" colspan="3">
					</td>
					<td class="end">
					</td>
					<td class="end">
					</td>
				</tr>
				<tr><td class="fbase"></td><td class="fbase"></td><td class="fbase"></td><td class="fbase"></td><td class="fbase"></td><td class="fbase"></td><td class="fbase"></td><td class="fbase"></td><td class="fbase"></td><td class="fbase"></td></tr>
			</tbody>
		</table>
	</body>
</html>

Суть вопроса: необходимо, чтобы по нажатию Add weekdays в пустую строку дублировалась часть строки выше(выпадающие списки), а следующие нажатия добавляли новые строки с дублированием строки выше. Строка, которая должна добавляться вот:

<tr>
					<td class="ext" colspan="3"></td>
					<td class="add" colspan="2">
						<span><select name="weekday"></select></span>
					</td>
					<td class="add" colspan="3">
						<span class="s1">from <select name="from"></select> till <select name="till"></select></span>
					</td>
					<td class="add">
						<span class="s1"><select name="classroom"></select></span>
					</td>
					<td class="add">
						<span></span>
					</td>
				</tr>

У кого есть идеи, буду очень признателен!!!!