Change the value of variable PHP

I have input fields, which I process with AJAX and send it on another file. The value of the inputs is always different. How in the file, where I get the data from AJAX, to change the variable id always when I get the data from AJAX.

Example: I get the data f开发者_开发技巧rom AJAX in this file:

<?php
$id=1;
echo '<div id="$id"></div>';
?>

Then I display the result in the page with AJAX.

I want the id of the div to be always different.

if you want $id a random number use the function randlink text

$id=rand(0,100); // random between 0 and 100, 0 and 100 incluse

you can also create a random string

function genRandomString($length) {
    $characters = '0123456789abcdefghijklmnopqrstuvwxyz';
    $string = '';
    for ($p = 0; $p < $length; $p++) {
        $string .= $characters[rand(0, strlen($characters))];
    }
    return $string;
}

One can create different random number through time checking, this will create random number on the basis of time and will generate different number each microseconds.

//this will add a char on the beginning of the value so it do not start with numeral

$str=range(a,z);

//using date function for generating random number

$i= $str[rand(0,25)].date('Ymzhisu');