如果没有SESSION或COOKIES,我可以获得'va'以保持它的价值吗?

<html>
<body>
    <p style='text-align:center;'>
    <?php 
        $wordChoices = array("grape","apple","orange","banana","plum","grapefruit");//Course provided aray/code
        if(isset($_POST['va']))
        {
            $randChoice=$_POST['va'];
            print("Trigger CONTINUE");
        }
        else
        {
            $randChoice=rand(0,5);
            print("Trigger New Rand");          
        }   

        //$randChoice = rand(0,5);//NEEDS FIX
        for($i=0;$i<=5;$i++)//output of array and green text
        {
            if($i==$randChoice)
                echo "<span style='color: green; text-align:center;'>$wordChoices[$i]</span>";//prints green word
            else
                echo "<span style='text-align:center;'>$wordChoices[$i]</span>";//print word
            if($i<5)//kills extrta "|"
                echo " | ";//print break between words

        }
        print_r($_POST);
    ?>
    </p>
    <h1 style='text-align:center;'>Word guess</h1>
    <div style='text-align:center'>
        <a href='game.php'>Refresh This Page</a>
    </div>
    <h3 style='text-align:center;'>Guess the word I'm thinking</h3>
    <form action="<?php $_SERVER['PHP_SELF'];?>" method='POST' style='text-align:center;'>
        <input type='text' name='tb1' placeholder=<?php echo $wordChoices[$randChoice];?>>
        <input type='submit' name='butt'>
        <input type='hidden' name='hid' value="">
    </form>
    <?php 
        if($_POST)
        {
            print_r($_POST);
                $_POST['va']=$randChoice;
            print("SET");
            print_r($_POST);
            if(isset($_POST['tb1']) && $_POST['tb1'] == $wordChoices[$randChoice])//checks to see if correct
                echo "<p style='text-align:center; color:red;'>You guessed " . $wordChoices[$randChoice]. " and that's CORRECT!!! (3)</p>";//prints out correct 
            else if(!isset($_POST['tb1'])||$_POST['tb1']=="")//checks if nothing entered
                echo "<p style='text-align:center; color:red;'>Come on, enter something (2)</p>";//prints out message to enter text
            else if(isset($_POST['tb1']) && isValid($_POST['tb1']) && strtoupper($_POST['tb1'])!=strtoupper($wordChoices[$randChoice]))//checks for valid guess but incorrect term
                echo "<p style='text-align:center; color:red;'>Sorry " . $_POST['tb1'] . " is wrong. Try again (4)</p>";//prints out valid incorrect guess
            else if(isset($_POST['tb1']) && !isValid($_POST['tb1']))//checks if guess is valid
                echo "<p style='text-align:center; color:red;'>Hey, that's not even a valid guess. Try again (5).</p>";//prints out invalid
        }
        else 
            echo "<p style='text-align:center; color:red;'>It's time to play the guessing game! (1)</p>";

        function isValid($textResp)//checks is guessed word is a valid word
        {
            print($textResp);
            $wordChoices = array("grape","apple","orange","banana","plum","grapefruit");
            if($textResp==$wordChoices[0])
                return true;
            else if($textResp==$wordChoices[1])
                return true;
            else if($textResp==$wordChoices[2])
                return true;                    
            else if($textResp==$wordChoices[3])                 
                return true;
            else if($textResp==$wordChoices[4])
                return true;
            else if($textResp==$wordChoices[5])
                return true;
            else
                return false;

        }
    ?>
</body>

Simply put I need the randChoice variable to reset or get a new random after the correct value is guessed. If the incorrect value is guessed, it should remain the same. Any ideas? I am new so there may be things I have not considered, buit remember without SESSION or COOKIES being used