PHP-Array search algorithm - php

Question

I have had a look at a few answers but none relates to my specific problem. I have an array that takes user input and sorts the array in an ascending order. That's all good, I now want the user to enter a number for which I can locate the array index, if the number is not located, the function returns -1. I cannot put my finger on the error, I'm getting -1 at all times.
Any help is truly appreciated
This is my form that picks up the information.
<form action="welcome.php" method="POST" value="">
Name: <input type="text" name="fname" value="">
Age: <input type="text" name="age" value="">
Integer :<input type="number" name="integer" value="">
<div class="container">
<p> Please choose numbers: </p>
<label>First:</label>
<input type="number" name="name[]" ><br />
<label>2nd</label>
<input type="number" name="name[]"><br />
<label>3rd</label>
<input type="number" name="name[]" ><br />
<label>4th</label>
<input type="number" name="name[]"><br />
<label>5th</label>
<input type="number" name="name[]"><br />
<label>6th</label>
<input type="number" name="name[]"><br />
<label>7th</label>
<input type="number" name="name[]"><br />
<label>8th</label>
<input type="number" name="name[]"><br />
<label>9th</label>
<input type="number" name="name[]"><br />
<label>10th</label>
<input type="number" name="name[]"><br />
<label>Pos Number</label>
<input type="number" name="pos"><br />
<input type="submit">
And the index locator:
Welcome <?php echo $_POST["fname"]; ?>!<br>
You are <?php echo $_POST["age"]; ?> years old.
<?php
$tmp = trim($_POST['integer']);
if (!ctype_digit($tmp)) {echo "Input requires an inetger " ;}
else{
echo "The integer is ".$_POST["integer"]."<br>";
}
echo"You have entered the numbers below <br>";
$name=$_POST['name'];
sort($name);
foreach( $name as $v) {
print $v."<br>";
}
echo "You wish to find the position of ".$_POST['pos']."<br />";
function search($name,$K){
$l=0;
$size=sizeof($name);
$u=$size-1;
$m=0;
while ($l<=$u){
$m = ($l+$u)/2;
round($m);
echo "this is m ".$m;
if ($name[$m]<$K) {
$l=$m+1;
}
else if ($name[$m]==$K) {
return $m;
return $m;
} else {
$u=$m-1;
}
}
return -1;
}
$po=$_POST['pos'];
$b=search($name,$po);
echo "The position of the entered number is".$b;
?>