too long

Im not sure how to introduce this, i have a problem... Okay well here is the code:

<button class="a2 menu-button-start" onclick="<?php echo "window.location.href = \"index.php?p=129&l=$lang\";"; ?>" id="a2a">Home</button>

Here is my problem: Its not taking me to the link.

I have not much to say other than the p variable defines the page, and the l variable defines the language. I dont think you need to know anything else.

<button class="a2 menu-button-start" onclick="<?php echo "window.location.href = 'index.php?p=129&l=" . $lang . "';"; ?>" id="a2a">Home</button>

try it like this:

<input type="button" value="Home" onclick="goToPage();" id="a2a">

<script>
function goToPage() {
<?php echo "window.location.href = 'index.php?p=129&l=' . $lang; . '";"' ?>
}
</script>

should be

     onclick="window.location.href=<?php echo 'index.php?p=129&l='.$lang;?>;" 

I would do it like this since you are only dynamically getting $lang:

<button class="a2 menu-button-start" onclick="window.location.href='index.php?p=129&l=<?php echo $lang ?>';" id="a2a">Home</button>