I am trying to call a custom made function (not mysql_* as in other questions suggested) from the index page. The index page is calling three custom functions. The first two are working correctly but the third function is throwing and error:
Fatal error: Uncaught Error: Call to undefined function display_index1() in F:\Apache24\htdocs\Site1\index.php:45 Stack trace: #0 {main} thrown in F:\Apache24\htdocs\Site1\index.php on line 45
This is my index page which is calling the function:
 <!DOCTYPE html>
    <?php 
    include("includes/connect.php");
    include("includes/functions.php"); 
    ?>
    <html>
    <head>
        <title>Ecommerce Website</title>
        <link rel="stylesheet" type="text/css" href="styles/style.css">
        <script src="js/style.js"></script>
    <body>
        <div class="container-fluid">
            <header>
                <div class="form">
                    <form method="get" target="" name="searchbar_form">
                        <input type="text" name="searchbar" id="searchbar">
                        <input type="submit" id="search_button" value="Search">
                    </form>
                </div>
            </header>
            <div class="menubar">
                    <div class="dropdown">
                        <button onclick="dropdownToggle()" class="dropdown-button">Shop By Category</button>
                            <ul class="dropdown-content" id="dropdownContent">
                                Categories
                                <?php getcats(); ?>
                                Brands
                                <?php getbrands(); ?>
                            </ul>
                    </div>
                <div class="menubar-div">
                    <ul class="menu-items">
                        <?php getcats(); ?>
                    </ul>
                </div>
                <div class="cart">
                    <a href="#">Cart</a>
                </div>
            </div>
            <div class="content">
                <div class="index_product_row">
                    <?php display_index1(); ?>
                </div>
            </div>
        </div>
        <div class="footer">
                This is footer
        </div>
    </body>
    </html>
This is the functions.php file which has the three called functions:
<?php 
    function getcats(){
        global $con;
        $get_cats="select * from categories";
        $run_cats=mysqli_query($con, $get_cats);
        while($row_cats=mysqli_fetch_array($run_cats)){
            $cat_id = $row_cats['cat_id'];
            $cat_title = $row_cats['cat_title'];
            echo "<li><a href='#'>$cat_title</a></li>";
        }
    }
    function getbrands(){
        global $con;
        $get_brands="select * from brands";
        $run_brands=mysqli_query($con, $get_brands);
        while($row_brands=mysqli_fetch_array($run_brands)){
            $brand_id = $row_brands['brand_id'];
            $brand_title = $row_brands['brand_title'];
            echo "<li><a href='#'>$brand_title</a></li>";
        }
    }
    function display_index1(){
        global $con;
        $display_query = "select(product_image, product_title) from products where product_cat='1'";
        $display_result = mysqli_query($con, $display_query);
        while($result_rows = mysqli_fetch_array($display_result)){
            $product_image = $result_rows['product_image'];
            $product_title = $result_rows['product_title'];
            echo "<img src='/admin/product_images/".$product_image."' width='200' height='200' alt='".$product_title."'/>";
            echo "<span id='index_product_title'>".$product_title."</span>";
        }
    }
?>
The first two functions are returning data successfully. Calling the third is returning the error.
 
    