使用jQuery和$ .ajax将变量传递给PHP

I have a jQuery php script which accesses a database and echoes back html to fill a div on my page. It uses the following code.

function myCall() {
    var request = $.ajax({
        url: "ajax.php",
        type: "GET",
        dataType: "html"
    });

    request.done(function (msg) {
        $("#divholder").html(msg);
    });

    request.fail(function (jqXHR, textStatus) {
        alert("Request failed: " + textStatus);
    });
}

What I need to do is also send a variable through to the script so it knows what to look for in the database. I have been searching but I can't seem to find quite the right answer. Any help greatly appreciated.

Regards.

You can send the parameter like this :

function myCall() {
    var request = $.ajax({
        url: "ajax.php?param1=" + 'parameter',
        type: "GET",            
        dataType: "html"
    });

    request.done(function(msg) {
        $("#divholder").html(msg);          
    });

    request.fail(function(jqXHR, textStatus) {
        alert( "Request failed: " + textStatus );
    });
}

And get the parameter with $_GET

Or you can send the parameter with POST (look at data : Ajax jQuery)

With a get request just append it to the url.

$.ajax({
    url : 'ajax.php?someVar=20',
    type : 'GET',
    dataType : 'html'
)}

You can also add it to the data property and jQuery will url encode your data and append it to the url string.

$.ajax({
    url : 'ajax.php',
    type : 'GET',
    dataType : 'html',
    data : {
        someVar : 20
    }
)}