ArraysInPHP - //Problem 3. Longest Increasing Sequence

//Problem 3.    Longest Increasing Sequence
//Write a script to find all increasing sequences inside an array of integers. The integers are given in a array. Print the sequences in //the order of their appearance in the input array, each at a single line. Separate the sequence elements by a space. Find also the //longest //increasing sequence and print it at the last line. If several sequences have the same longest length, print the leftmost of //them. //Examples:
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <form action="LongestIncreasingSequence.php" method="post">
        <input type="text" name="text">
        <input type="submit" value="enter!">
        </form>
    </body>
</html>
<?php
$myString = $_POST['text'];
$myArray=explode(" ", $myString);
        for ($i = 0; $i <= count($myArray); $i++)
        {
            if ($myArray[$i-1] < $myArray[$i])
            {
                $stringBuild.=$myArray[$i]." ";
            }
            else{
                $newArr[]=$stringBuild;
                $stringBuild=$myArray[$i]." ";
            }
        }
        echo '<pre>' . print_r($newArr, true) . '</pre>';
        $longest =$newArr[0];
        $maxValue=0;
        for($z=0;$z<=count($newArr);$z++){
            $counter=substr_count($newArr[$z], " ");
            if ($counter>$maxValue) {
                $maxValue=$counter;
            }
            if ($maxValue < substr_count($newArr[$z+1], " ")){
                $longest=$newArr[$z+1];
            }
        }
        echo 'Longest is: '.$longest;
?>