Pagination All from sql and Pagination of Alphabetical navigate - php

Question

I used Pagination in php with mysqli and Alphabetical navigator in same page. They are working well. But if I click on any Alphabet like: B Its display 10 sql table's data with B and when I click page 2 to display rest of data Alphabet B, Its cannot display rest of data B but display next 10 data of all sql table's.
I have Total 100 row in sql where for A=20, b=30, c=5, d=15 ... etc. I used Pagination for display 10 data at a time And Alphabetical navigator to display data as Alphabet.
Now I want:
When user load my page, Pagination work for all data by name ASC limit 10, But when user click on any Alphabet, Pagination work for this Alphabet.
Here is my code:
<?php
include_once('db.php');
//for pagination
$limit = 10;
if (isset($_GET["page"])) { $page = $_GET["page"]; } else { $page=1; };
$start_from = ($page-1) * $limit;
//for Alphabet
$sort = isset($_GET['firstLetter']) ? filter_input(INPUT_GET, 'firstLetter',FILTER_SANITIZE_URL) : "" ;
if($sort == "") {
$sql = "SELECT * FROM evideo ORDER BY name ASC LIMIT $start_from, $limit";
}else{
$sql = "SELECT * FROM evideo WHERE Name LIKE '$sort%' ORDER BY name ASC LIMIT $start_from, $limit" ;
}
$execute = $dbh->query("$sql");
//Display Alphabet
echo '<div class="well abc-pag"><b>Find Alphabetically:</b> ';
for ($i = 65; $i < 91; $i++) {
printf('%s ', $_SERVER['PHP_SELF'] , chr($i), chr($i));
}
printf('ALL', $_SERVER['PHP_SELF'] );
echo "</div>";
$rowcount = $execute->num_rows ;
$c = 1;
if ($rowcount > 0 ) {
$row = $dbh->query($sql) ;
while ($row = $execute->fetch_assoc()) {
$name = $row['name'];
$Detail = $row['Detail'];
$link = $row['link'];
$pic = $row['pic'];
if (empty($pic)) $pic = "../images/edir.jpg";
echo '<article class="white-panel"><a href="'.$link.'">';
echo '<img src="images/loader.gif" border="0" data-echo="'.$pic.'" class="emusicpro img-responsive"></a>';
echo '<div class="well"><strong>'.$name.'</strong><br>'.$Detail.'</div>';
echo '</article>';
}
} else {echo '<p align="center"><b>No Data Found.</b></p>';}
//Display pagination
$sql = "SELECT COUNT(id) FROM evideo";
$rs_result = mysqli_query($dbh,$sql);
$row = mysqli_fetch_row($rs_result);
$total_records = $row[0];
$total_pages = ceil($total_records / $limit);
$pagLink = "<ul class='pagination'>";
for ($i=1; $i<=$total_pages; $i++) {
$pagLink .= "<li><a href='ebox2.php?page=".$i."'>".$i."</a></li>";
};
echo $pagLink . "</ul>";