Question

I made some javascript code for my website, it works without problem on opera and chrome, but not on firefox.

Here is script:

function checkstate(who,row,cell)   {
    var zwrot="";
    var mouseEvent='onmouseover="javascript:bubelon(this.id);" onmouseout="bubeloff();"';
    var cellid="";

    ajax=new XMLHttpRequest();
    ajax.onreadystatechange=function(aEvt) {
        if (ajax.readyState===4 && ajax.status===200) {
            alert("im here!");
            }
    };

    ajax.open('GET',"oth/work_prac_stan.php?usr="+who,false);
    ajax.send();
}

function sprawdzstan() {
    var lol="";
    var table = document.getElementById("usery");
    var re = /^<a\shref\=/g;

    for (var i = 1, row; row = table.rows[i]; i ++) {
        if (row.cells[0].innerHTML.match(re)) {
            checkstate(row.cells[1].innerHTML,row,2);
        } else {
            checkstate(row.cells[0].innerHTML,row,1);
        }
    }
}

The problem is, that firefox is not running function assigned to onreadystatechange. I checked in firebug, that response from php file is correct.

Where is the problem? It works on chrome and opera, firefox just dont, no error in console, nothing.

Answer 1

Updated answer

According to Mozilla’s docs, you don’t use onreadystatechange with synchronous requests. Which kind of makes sense, since the request doesn’t return until the ready state is 4 (completed), though I probably wouldn’t have designed it that way.

Original answer

Not immediately seeing a smoking gun, but: Your ajax variable is not defined within the function, and so you’re almost certainly overwriting it on every iteration of the loop in sprawdzstan. Whether that’s a problem remains to be seen, since you’re using a synchronous ajax call. In any case, add a var ajax; to checkstate to ensure that you’re not falling prey to the Horror of Implicit Globals.

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Off-topic: If you can possibly find a way to refactor your design to not use a synchronous ajax request, strongly recommend doing that. Synchronous requests lock up the UI of the browser (to a greater or lesser degree depending on the browser, but many — most? — completely lock up, including other unrelated tabs). It’s almost always possible to refactor and use an asynchronous request instead.

Off-topic 2: You aren’t using mouseEvent in your code, but if you were, you would want to get rid of those javascript: prefixes on the onmouseover and onmouseout attributes. Those attributes are not URLs, the prefix is not (there) a protocol specifier (it’s a label, which you’re not using).