分页不起作用？

Question

的index.php

<script>
    $(document).ready(function() {
        $("#submit").click(function() {
            course = $("#courses").val();
            field2 = $("#field2").val();
            $("#imagen").show();
            $.ajax({
                type: "POST",
                data: {
                    "courses": course,
                    "field2": field2
                },
                url: "all_college.php",
                success: function(data) {
                    $("#imagen").hide();
                    $("#popular_colleges").html(data);
                }
            });
        });
    });
</script>
<img id="imagen" src="images/please.gif">
<div id="popular_colleges"></div>

all_college.php

<?php
    $course = $_POST['courses'];
    $field2 = $_POST['field2'];

    $per_page=10;
    if (isset($_GET["page"])) 
    {
        $page = $_GET["page"];
    }
    else 
    {
        $page=1;
    }
    $start_from = ($page-1) * $per_page;

    $sql = "select * from all_colleges where courses like '%,$course,%' LIMIT $start_from, $per_page";
    $result = mysqli_query($link,$sql);
    while($row = mysqli_fetch_array($result))
    {
?>
        <?php echo $row['college_name']; ?>
        <?php echo $row['address']; ?>
<?php
    }
?>

<?php
    $query = "select * from all_colleges";
    $result = mysqli_query($link, $query);
    $total_records = mysqli_num_rows($result);
    $total_pages = ceil($total_records / $per_page);
    echo "<center><a href='index.php?page=1' style='padding:10px;'>".'First Page'."</a>";
    $skipped = false;
    for ($i = 1; $i <= $total_pages; $i++)  {
        if ($i < 3 || $total_pages- $i < 3 || abs($page - $i) < 3) {
            if ($skipped)
                echo '<span> ... </span>';
            $skipped = false;
            echo "<a href='index.php?page=" . $i . "' style='padding:5px;'>" . $i . "</a>";
        } else {
            $skipped = true;
        }
    }
    echo "<a href='index.php?page=$total_pages' style='padding:10px;'>".'Last Page'."</a></center>";
?>

在此代码中，当我点击提交按钮时，它将显示最多10个结果，因为我定义$ per_page = 10并且分页编号也显示但是当我点击任意数量的分页时假设我点击2然后索引页面重新加载和数据不会显示。那么，我该如何解决这个问题呢？请帮忙。

谢谢