[BCSE]

I just installed this on a 4.0.4 version today. Here's the code I used:

In cart.php After:

x_session_register("cart");
x_session_register("intershipper_rates");
x_session_register("intershipper_recalc");
x_session_unregister("secure_oid");
x_session_register("extended_userinfo");
x_session_register("anonymous_checkout");
x_session_register("payment_cc_fields");
x_session_register("current_carrier");

Insert:

x_session_register("zipcode_estimate");

if($zip_estimate == "clear")
{
      $zipcode_estimate = "";
      func_header_location("cart.php");
}
   
if(!empty($zip_estimate))
{
      $zipcode_estimate = $zip_estimate;
      
      $count = substr_count($zipcode_estimate,"0") + substr_count($zipcode_estimate,"1") + substr_count($zipcode_estimate,"2") + substr_count($zipcode_estimate,"3") + substr_count($zipcode_estimate,"4") + substr_count($zipcode_estimate,"5") + substr_count($zipcode_estimate,"6") + substr_count($zipcode_estimate,"7") + substr_count($zipcode_estimate,"8") + substr_count($zipcode_estimate,"9");

      if($count != 5){  //checking for 5 digits
          $zipcode_estimate = "";}
      if($mode=="checkout")
      	func_header_location("cart.php?mode=checkout");
      else        
        func_header_location("cart.php");
}
if($zipcode_estimate != "")
{
      $config["General"]["apply_default_country"] = "Y";
      $config["General"]["default_zipcode"] = $zipcode_estimate;
      $smarty->assign("estimate","NO");
} 

Then in skin1/customer/main/cart_totals.tpl Before:

{if $not_logged_message eq "1"}{$lng.txt_order_total_msg}{/if}

Add:

{* BCSE Begin *}
{if $login}
{else}
	{if $estimate ne "NO"}
	     
Enter your zip code to calculate shipping charges.

		<input type=TEXT name='zip_estimate' size=5 maxlength=5>
		{include file="buttons/button.tpl" button_title="Calculate Shipping" href="javascript: document.cartform.submit()"  js_to_href="Y"}
		
	   {else} 

Click here to change your zip code

	  {/if}
	  


{/if} 
{* BCSE End *}

Hope this helps! Thanks for the original code rackit!

Carrie