如何使用URL传递变量

I am trying to pass 2 values via URL to another page. I know how to do this however I am taking one of the values from the result of select box. I am grabbing the selected value and storing it in a variable then attempting to post this variable in the URL.

option 1 is storing the selected value.

<select name = 'ADDITIONALINFO' id = 'ADDITIONALINFO'>
    <option value="1">Option 1</option>
      <option value="2">Option 2</option>
      <option value="3">Option 3</option>
      <option value="4">Option 4</option>
</select>

<script>
        var sel = document.getElementById("ADDITIONALINFO");

        sel.onchange = function()
        {
            var option1 = sel.options[sel.selectedIndex].text;
            alert(option1);
        };
        </script>

        <?php


        echo "<div class=\"add-button-quote\"><a href=\"/quotation/index.php?sku=" . $product->PR_SKU . "&OP_NAME=" . $option1 . "&OP_NAME2=" . $o->OP_NAME . "\">Get a Quotation</a></div>";

The problem Im having is when I click the button the URL it takes me too displays the $sku but not $option1.

If anyone can spot where Ive gone wrong I would really appreciate your advice. Thanks!

$option1 is not defined in PHP (it's a variable in JavaScript, right?) You can not mix up JS and php in that way ;)

Give the div an id and change javascript function to:

sel.onchange = function()
{
    var option1 = sel.options[sel.selectedIndex].text;
    document.getElementById("add-button-quote").innerHTML = "<a href='/quotation/index.php?sku=<?php echo $product->PR_SKU;?>&OP_NAME="+encodeURIComponent(option1)+"&OP_NAME2=<?php echo $o->OP_NAME;?>'>Get a Quotation</a>";
    alert(option1);
};

Or give anchor an id and the same way manipulate its href attribute.

Use onclick instead of onchange, it should do the trick...Like @Florian asks, why not using a form?

Also, you should define option1 outside onclick/onchange scope, and use it as a javascript variable, without '$', once it is not a PHP variable

PHP is not run while the page is active, it's only run until the page is loaded. From there you have to rely on javascript.

If $product->PR_SKU and $o->OP_NAME is set by PHP you don't have to change that part, but remove OP_NAME from the url. After getting the option selected you can then add the parameter by javascript.

Notice that you might want to store the baseUrl somewhere else instead of writing like below, where you will potentially get duplicates of the parameter:

document.getElementById("your-link").href += "&OP_NAME=" + option1;

Do like this instead:

var baseUrl = <?php echo "/quotation/index.php?sku=" . $product->PR_SKU . "&OP_NAME2=" . $o->OP_NAME; ?>

var sel = document.getElementById("ADDITIONALINFO");
sel.onchange = function()
{
    var option1 = sel.options[sel.selectedIndex].text;
    document.getElementById("your-link").href = baseUrl + "&OP_NAME=" + option1;
};

Your div can look like this (notice the removal of option1 and the id='your-link':

<?php
echo "<div class=\"add-button-quote\"><a id=\"your-link\" href=\"/quotation/index.php?sku=" . $product->PR_SKU . "&OP_NAME2=" . $o->OP_NAME . "\">Get a Quotation</a></div>";
?>

Here is an example of form with POST method with javascript onchange event -etched- directly to select tag. This should work *(haven't tested though) and if it does, it won't take a lot of Your time to adapt this to GET instead of POST.

<form id="UNIQUEID" method="POST" action="#">
    <select id="ADDITIONALINFO" name="ADDITIONALINFO" onchange="document.forms['UNIQUEID'].submit();">
        <option value="1">Option 1</option>
        <option value="2">Option 2</option>
        <option value="3">Option 3</option>
        <option value="4">Option 4</option>
    </select>
</form>   

One more thing...

USE singlequotes when mixing php and html - wherever possible and don't forget to write php close tag.. ?> - ALSO .. this -> & should be & inside href tag when url query is not -text/plain- (javascript) but -text/html-.

Example with php shortEcho:

<?= instead of <?php echo (I assume that Your server is configured to use php shorthands):

<?='<div class="add-button-quote"> <a href="/quotation/index.php?sku='.$product->PR_SKU.'&amp;OP_NAME='.$option1.'&amp;OP_NAME2='.$o->OP_NAME.'">Get a Quotation</a> </div>'; ?>

HOwever, as people already stated here, $option1 variable is not going to work on the way You want.

With additional $option1=$_GET['ADDITIONALINFO']; or $option1=$_POST['ADDITIONALINFO']; (whichever You decide to use, depending on form method) somewhere in between, and before <div class="add-button-quote"> .. might work. :)