Unable to click on toggle dropdown link

I'm having trouble with the shopping cart toggle drop down, When I click the drop down the link doesn't take me to the link location but does on everything else.

Here is my coding, am i doing anything wrong? Any help would be great.

$(document).ready(function(){

// Drop Menu


$('.navigation > ul > li > a').click(function(e){
    if($(this).parent().hasClass('current')){
        $(this).parent().removeClass('current');
    }else{
        $(this).parent().addClass('current');
    }
    if($(this).parent().find('ul')){
        e.preventDefault();
    }
});

$('.shoppingbasket > ul > li').click(function(e){
    if($(this).hasClass('current')){
        $(this).removeClass('current');
    }else{
        $(this).addClass('current');
    }
    if($(this).parent().find('ul')){
        开发者_开发知识库e.preventDefault();
    }
});

$(".navigation ul ul, .shoppingbasket ul ul").css({display: "none"});
$(".navigation ul li, .shoppingbasket ul li").click(function(){
    $(this).find('ul:first').slideToggle(400);
});
});

There are few issues in your code, try this

$(document).ready(function(){

// Drop Menu


$('.navigation > ul > li > a').click(function(e){
    var $parent = $(this).parent();
    if($parent.hasClass('current')){
        $parent.removeClass('current');
    }else{
        $parent.addClass('current');
    }   
    if($parent.find('ul').length > 0){
        e.preventDefault();
    }
});

$('.shoppingbasket > ul > li').click(function(e){
    var $this = $(this);
    if($this.hasClass('current')){
        $this.removeClass('current');
    }else{
        $this.addClass('current');
    }   
    if($this.parent().find('ul').length){
        e.preventDefault();
    }
});

//This will stop the event propagation from sub menus    
$('ul.sub-menu').click(function(e){
  e.stopPropagation();
});

$(".navigation ul ul, .shoppingbasket ul ul").css({display: "none"});
$(".navigation ul li, .shoppingbasket ul li").click(function(){
    $(this).find('ul:first').slideToggle(400);
});
});

In your markup for the shopping cart links the only thing I see different than the other links is a target attribute.

<a class="visitshop" title="Visit Shop" href="http://www.media21a.co.uk/clientlogin/benaiahmatheson/products-page/" target="_parent">Visit the shop</a>

Try removing this attribute:

target="_parent"