Select make checkbox

This functions used select data but I want use <input type="checkbox"/>

Please help to modify.

//----------get country via select option----------
function get_country()
{
    
    $sql = "SELECT id,country FROM countries ORDER BY id ASC";
    $res = mysql_query($sql);
        
    echo "<select id=\"country\" class=\"searchbox\" name=\"country\">";
        echo "<option value=\"\">Select One</option>";
        while ($row = mysql_fetch_assoc($res)){
            echo "<option value=\"".$row['country']."\">".$row['country']."</option>";
            }
    echo "</select>";
}

//----------get countries via select option from users----------
function get_select_countries($id)
{
    $id = secureInput($id);
    
    $sql = "SELECT country FROM countries ORDER BY country ASC";
    $res = mysql_query($sql);
        
    $sql1 = "SELECT country FROM users WHERE id='".$id."'";
    $res1 = mysql_query($sql1);
    $row1 = mysql_fetch_assoc($res1);
    
    if($row1){
        echo "<select name=\"country\">";
        echo "<option selected=".$row1['country']." value=\"".$row1['country']."\">".$row1['country']."</option>";
        while ($row = mysql_fetch_assoc($res)){
            echo "<option value=\"".$row['country']."\">".$row['country']."</option>";
            }
        echo "</select>";
        } else {
            echo "<select name=\"country\">";
            while ($row = mysql_fetch_assoc($res)){
                echo "<option value=\"".$row['country']."\">".$row['country']."</option>";
            }
            echo "</select>";
    }
}