How to pass multiple parameters by jQuery.ajax() to PHP?

I have a si开发者_开发知识库mple load more style script that works fine on the index page, where only one parameter is sent via ajax

    $(function() {//When the Dom is ready
    $('.load_more').live("click",function() {//If user clicks on hyperlink with class  name = load_more
        var last_msg_id = $(this).attr("id");//Get the id of this hyperlink this id indicate the row id in the database
        if(last_msg_id!='end'){//if  the hyperlink id is not equal to "end"
            $.ajax({//Make the Ajax Request
                type: "POST",
                url: "index_more.php",
                data: "lastmsg="+ last_msg_id,
                beforeSend:  function() {
                    $('a.load_more').html('<img src="loading.gif" />');//Loading image during the Ajax Request
                },
                success: function(html){//html = the server response html code
                    $("#more").remove();//Remove the div with id=more
                    $("ul#updates").append(html);//Append the html returned by the server .
                }
            });
        }
        return false;
    });
});

With this HTML/PHP

<div id="more">
 <a  id="<?php echo $msg_id; ?>" class="load_more" href="#">more</a>
</div>

However, I want to add another php variable so that it can also work with particular categories, I have no problems writing the HTML and PHP but I am new to Jquery and struggling to edit the script to include the additional parameter if it is set. This is the HTML that I am thinking of using, just struggling with editing the JQuery

<div id="more"class="<?php echo $cat_id;?>">
<a id="<?php echo $msg_id;?>" class="load_more2" href="#">more</a>
</div>

As always any help is much appreciated!

You can set

data = {onevar:'oneval', twovar:'twoval'}

And both key/value pairs will be sent.

See Jquery ajax docs

If you look under the data section, you can see that you can pass a query string like you are, an array, or an object. If you were to use the same method you already are using then your data value would be like "lastmsg="+ last_msg_id + "&otherthing=" + otherthing,

You can pass multiple URL params in the data portion of your ajax call.

data: "lastmsg="+ last_msg_id +"&otherparam="+ other_param

On the PHP side, you'd just process these as you already are.

You can use this code:

$.ajax({//Make the Ajax Request
                type: "POST",
                url: "index_more.php",
                data: {var1: "value1", var2: "value2"},
                beforeSend:  function() {
                    $('a.load_more').html('<img src="loading.gif" />');//Loading image during the Ajax Request
                },
                success: function(html){//html = the server response html code
                    $("#more").remove();//Remove the div with id=more
                    $("ul#updates").append(html);//Append the html returned by the server .
                }
            });

Try It:

data: JSON.stringify({ lastmsg: last_msg_id, secondparam: second_param_value});

You can add more parameters separating them by comma (,).