CSS

Первый вариант:

.pricing-table .zakaz{width:80px;height:20px;position: relative;padding: 10px 45px;color: #fff;font: bold 17px Verdana;text-transform: none;text-decoration: none;display: inline-block;background-color: #72ce3f;-moz-border-radius: 10px;-webkit-border-radius: 10px;border-radius: 10px;text-shadow: 0 -1px 0 rgba(0,0,0,.15);opacity: .9;margin: 0px 0px 0px 25px;}
.pricing-table .zakaz:hover{opacity: 1;}
.pricing-table .zakaz:active{-moz-box-shadow: 0 2px 2px rgba(0,0,0,.3) inset;-webkit-box-shadow: 0 2px 2px rgba(0,0,0,.3) inset;box-shadow: 0 2px 2px rgba(0,0,0,.3) inset;}			
.pricing-table .site-vizit .zakaz{background-color: #f56e15;background-image: url(../images/22.png);background-repeat: no-repeat;background-position: 15px 14px;}
#submit { display:none; }

<div class="pricing-table">
    <div class="site-vizit">
        <input id="submit" type="submit" onclick="alert('');" value="">
        <a class="zakaz" title='Заказать разработку сайта' href="javascript://" onclick="submit.click();">Заказать</a>       
    </div >

Второй, к тегу form добавить атрибут с id, допустим id="subform":

.pricing-table .zakaz{width:80px;height:20px;position: relative;padding: 10px 45px;color: #fff;font: bold 17px Verdana;text-transform: none;text-decoration: none;display: inline-block;background-color: #72ce3f;-moz-border-radius: 10px;-webkit-border-radius: 10px;border-radius: 10px;text-shadow: 0 -1px 0 rgba(0,0,0,.15);opacity: .9;margin: 0px 0px 0px 25px;}
.pricing-table .zakaz:hover{opacity: 1;}
.pricing-table .zakaz:active{-moz-box-shadow: 0 2px 2px rgba(0,0,0,.3) inset;-webkit-box-shadow: 0 2px 2px rgba(0,0,0,.3) inset;box-shadow: 0 2px 2px rgba(0,0,0,.3) inset;}			
.pricing-table .site-vizit .zakaz{background-color: #f56e15;background-image: url(../images/22.png);background-repeat: no-repeat;background-position: 15px 14px;}
#submit { display:none; }

<form id="subform" method="post" onsubmit="alert('');">
<div class="pricing-table">
    <div class="site-vizit">
        <a class="zakaz" title='Заказать разработку сайта' href="javascript://" onclick="subform.onsubmit();">Заказать</a>       
    </div >
</form>