У меня есть школьный проект по созданию системы заказа книг с использованием HTML и javascript, мы должны использовать javascript, чтобы получить общую цену книги, умножив поле количества на цену за единицу, а затем мы должны просуммировать все столбцы общей цены, чтобы получить общую цену. У меня вопрос, как будет выглядеть javascript, как будто я пробовал некоторые функции, но, похоже, он не работает. вот мой HTML файл. Можете ли вы помочь мне написать функцию, удовлетворяющую требованиям
<head> <h1 style="font-family:times new roman; font-size: 18pt">Book Ordering Seystem</h1>
<link rel="stylesheet" href="homestyle.css">
</head>
<br>
<table class="tg" id ="table">
<thead>
<tr>
<th class="tg-eh3c">No.</th>
<th class="tg-qu9t">Book Title</th>
<th class="tg-qu9t">Author </th>
<th class="tg-qu9t">Category</th>
<th class="tg-qu9t">Unit price</th>
<th class="tg-eh3c">Quantity</th>
<th class="tg-eh3c">Total</th>
</tr>
</thead>
<tbody>
<tr>
<td class="tg-nt2e">1</td>
<td class="tg-4msd"><input type="text"></td>
<td class="tg-v4tt"><input type="text"></td>
<td class="tg-v4tt">
<select name="Category" class="Category">
<option value="Category">Please choose the Category...</option>
<option value="Business">Business</option>
<option value="Fiction">Fiction</option>
<option value="Mathematics">Mathematics</option>
<option value="Technology">Technology</option>
</select></td>
<td class="tg-0tzc"><input id="up1" type="number" placeholder="0.00" step="0.00" style="text-align: right"></td>
<td class="tg-kgwd"><input id="qn1" type="number" placeholder="0" step="0" style="text-align: right"></td>
<td class="tg-kgwd"><input id="total1" type="number" placeholder="0.00" step="0.00" style="text-align: right ; background-color:silver"readonly value=0>
</td>
</tr>
<tr>
<td class="tg-nt2e">2</td>
<td class="tg-4msd"><input type="text"></td>
<td class="tg-v4tt"><input type="text"></td>
<td class="tg-v4tt">
<select name="Category" class="Category">
<option value="Category">Please choose the Category...</option>
<option value="Business">Business</option>
<option value="Fiction">Fiction</option>
<option value="Mathematics">Mathematics</option>
<option value="Technology">Technology</option></select>
</td>
<td class="tg-0tzc"><input id="up2" type="number" placeholder="0.00" step="0.00" style="text-align: right"></td>
<td class="tg-kgwd"><input id="qn2" type="number" placeholder="0" step="0" style="text-align: right"></td>
<td class="tg-kgwd"><input id="total2" type="number" placeholder="0.00" step="0.00" style="text-align: right ; background-color:silver"readonly></td>
</tr>
<tr>
<td class="tg-nt2e">3</td>
<td class="tg-4msd"><input type="text"></td>
<td class="tg-v4tt"><input type="text"></td>
<td class="tg-v4tt">
<select name="Category" id="Category">
<option value="Category">Please choose the Category...</option>
<option value="Business">Business</option>
<option value="Fiction">Fiction</option>
<option value="Mathematics">Mathematics</option>
<option value="Technology">Technology</option></select>
</td>
<td class="tg-0tzc"><input id="up3" type="number" placeholder="0.00" step="0.00" style="text-align: right"></td>
<td class="tg-kgwd"><input id="qn3" type="number" placeholder="0" step="0" style="text-align: right"></td>
<td class="tg-kgwd"><input id="total3" type="number" placeholder="0.00" step="0.00" style="text-align: right ; background-color:silver"readonly></td>
</tr>
<tr>
<td class="tg-nt2e">4</td>
<td class="tg-4msd"><input type="text"></td>
<td class="tg-v4tt"><input type="text"></td>
<td class="tg-v4tt">
<select name="Category" class="Category">
<option value="Category">Please choose the Category...</option>
<option value="Business">Business</option>
<option value="Fiction">Fiction</option>
<option value="Mathematics">Mathematics</option>
<option value="Technology">Technology</option></select>
</td>
<td class="tg-0tzc"><input id="up4" type="number" placeholder="0.00" step="0.00" style="text-align: right"></td>
<td class="tg-kgwd"><input id="qn4" type="number" placeholder="0" step="0" style="text-align: right"></td>
<td class="tg-kgwd"><input id="total4" type="number" placeholder="0.00" step="0.00" style="text-align: right ; background-color:silver"readonly></td>
</tr>
<tr>
<td class="tg-nt2e">5</td>
<td class="tg-4msd"><input type="text"></td>
<td class="tg-v4tt"><input type="text"></td>
<td class="tg-v4tt">
<select name="Category" class="Category">
<option value="Category">Please choose the Category...</option>
<option value="Business">Business</option>
<option value="Fiction">Fiction</option>
<option value="Mathematics">Mathematics</option>
<option value="Technology">Technology</option></select>
</td>
<td class="tg-0tzc"><input id="up5" type="number" placeholder="0.00" step="0.00" style="text-align: right"></td>
<td class="tg-kgwd"><input id="qn5" type="number" placeholder="0" step="0" style="text-align: right"></td>
<td class="tg-kgwd"><input id="total5" type="number" placeholder="0.00" step="0.00" style="text-align: right ; background-color:silver"readonly></td>
</tr>
<tr>
<td class="tg-ts62" colspan="6"><button id="result" type="button" onClick="multiply(); calculatetotal();" style="float: right;" >Calculate Grand Total Price</button></td>
<td class="tg-rviu"><input type="number" placeholder="0.00" step="0.00" style="text-align: right; background-color:silver; font-size: 18pt" readonly></td>
</tr>
</tbody>
</table>