use the same technique as you did in the first column of the row
<c:forEach var="product" items="${myArrayList}">
<tr>
<td><c:out value="${product.reqid}"></c:out></td>
<td><c:out value="${product.proid}"></c:out></td>
<td><c:out value="${product.proname}"></c:out></td>
<td><c:out value="${product.username}"></c:out></td>
<input type ="hidden" name="reqno" value="<c:out value="${product.reqid}"/>">
<td><input type="submit" value="Approve"></td>
</tr>
</c:forEach>