Pasar datos por un formulario con link

<form method="post">
        <select class="styled" name="type" id="type">
			<option value="facebook"></option>
	</select>
<input type="submit" value="Enviar" />

<a class="type" data-value="facebook">Facebook</a>

if(isset($_POST['type'])){
	$type = $db->EscapeString($_POST['type']);

<form method="post">
        <input type="hidden" id="type">
<input type="submit" value="Enviar" />

<a class="type" data-value="facebook">Facebook</a>
<a class="type" data-value="google">Googe</a>
<a class="type" data-value="twitter">Twitter</a>

window.onload = function(){
var input = document.getElementById('type');
var btns = document.getElementsByClassName('type');
for(var i = 0; i < btns.length; i++) {
btns[i].onclick = function(){
input.value = this.getAttribute('data-value');
return false;
}
}
}