Untitled

auto checkbox based from url value using javascript/jQuery
?type=A&type=C or ?type=D

<form name="input" action="" method="post" ><br />
Select Type: <br />
<input type="checkbox" name = "type" value="A" /> A <br />
<input type="checkbox" name = "type" value="B"  /> B <br />
<input type="checkbox" name = "type" value="C"  /> C <br />
<input type="checkbox" name = "type" value="D" /> D <br /> <br />
<input type="submit" value="Submit" />

var i = document.location.href.lastIndexOf('?');
var types = document.location.href.substr(i+1).replace(/type=/g,'').split('&');
$('input[name="type"]').prop('checked',function(){
     return $.inArray(this.value,types) !== -1;
});

"type=A&type=C"

"A&C"   //after replace

["A","C"]

$('input[value="A"]').prop("checked", true);