Ajax array, checkbox y select multiple

[GatorV]

Código javascript:

var checks = document.forms['miforma'].elements['mis_checks'];
var checkboxes = [];
for(var i = 0; i < checks.length; i++ ) {
      if(checks[i].checked) {
            checkboxes.push(checks[i].name + "=" + checks[i].value);
      }
}
 
alert(checkboxes.join('&'));
 

Saludos.