The ping API will return true if CometChat has been loaded.

API:

jqcc.cometchat.ping()

Sample:

document.onload = function() {
    testload();
}
 
function testload(data) {
    var loaded = 0;
    try {
        loaded = jqcc.cometchat.ping();
    } catch (err) {
 
    }
 
    if (loaded) {
        alert('CometChat has loaded');
    }
}