Php 从文本框到URL获取值

我有一个php代码来生成链接。（此代码只需在用户URL之前添加我的URL

<?php 
    if(isset($_POST["submit"])){
        $link = $_POST["link"];
        echo '<a href="http://onlinedealsindia.in/go.php?url="$link"">Buy Now</a>';
    }
?>
<input type="url" class="form-control" name="link" placeholder="Enter Product URL" required>
<input class="button" type="submit" name="submit" value="Submit">

我希望用户的URL添加到echo中我的URL.Like-URL）之后，如上图所示。提交时，用户会收到ans回音，并在我的网站URL后添加一个链接。

<?php 
if(isset($_POST["submit"])){
$link = $_POST["link"];
echo '<a href="http://onlinedealsindia.in/go.php?url='.$link.'">Buy Now</a>';// corrected incorrect usage of quotes
}
?>
<form accept="" action="" method="post"> <!-- added form open -->       
<input type="url" class="form-control" name="link" placeholder="Enter Product URL" required>
<input class="button" type="submit" name="submit" value="Submit">
</form> <!-- added form closing-->