Question

Whats the best way to convert this code to jquery? I tried it this way but noticed that internet explorer gives me trouble with this. So I decided to do it with jQuery but I see a lot of methods but I dont know how to make the same function with it.

function updateField(str, id, prevvalue, value, vehicletype) {
    if (str == "") {
        document.getElementById(id).innerHTML = "";
        return;
    }
    if (window.XMLHttpRequest) { // code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp = new XMLHttpRequest();
    } else { // code for IE6, IE5
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    xmlhttp.onreadystatechange = function () {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
            document.getElementById(id).innerHTML = xmlhttp.responseText;
        }
    }
    xmlhttp.open("GET", "inc/form_rest.php?q=" + str + "&prevvalue=" + prevvalue + "&value=" + value + "&vehicletype=" + vehicletype, true);
    xmlhttp.send();
}

Answer 1

The simplest would be to use get :

$.get("inc/form_rest.php",
    {q:str, prevvalue:prevvalue, value:value, vehicletype:vehicletype},
    function(html){
       $('#'+id).html(html);
    }
);

Note that I let jQuery build the url, which will also ensure that the urlencoding is properly done.

As you’re only using the response to fill an element, you could also have used

$('#'+id).load(
   "inc/form_rest.php?q=" + str + "&prevvalue=" + prevvalue + "&value=" + value + "&vehicletype=" + vehicletype
);