How Can I add currency selector on WHMCS custom page?

I am trying to add a currency selector on one of my custom pages where I have displayed the product details.
I want to allow my visitor to change the default currency from this custom page and view the product pricing accordingly.

I have added this code in my custom.tpl


``` <form method="post" action="" >
<input type="hidden" name="token" value="{$LANG.go}">
<select name="currency" onchange="submit()" class="form-control">
<option value="">Change Currency (A$ AUD)</option>
{foreach from=$currencies item=listcurr}
<option value="{$listcurr.id}"{if $listcurr.id == $currency.id} selected{/if}>{$listcurr.prefix} {$listcurr.code}</option>
{/foreach}
</select>
</form> ```



But it is not working, every time I select the currency from the dropdown, it refreshes the page. but nothing changes,
please guide what I am doing wrong.

Thanks in advance
Aqsa,