Preventing Ajax save data two times - ajax

Question

Whenever I run Ajax in jquery, it will run two times. It will cause a problem in saving data. I googled and used their metods but none of them worked. The following is the ways I tried:
Set a global flag. Set it on when Ajax is running, turn it off after done. It seems that duplicated calls manage the flag concurrently. Before call 1 closed the door, call 2 is already in in no time. Or check time if less than 4000, do not run Ajax.
Generating a random number and attach to the url, they are the same always.
event.preventPropgador();e.preventDefault(); does not work in whichever order
async:true or false does not work
I cannot use "once" since I am usimg jQuery Mobile
$("#submitButton").once("tap", function () { //<-- error
save();
});
used "one" but not work
$("#submitButton").one("tap", function () {
save();
});
disable the button when ajax running, then enable it afterwords.
I tried above techs on save() and Ajax calls, none of them worked.
This is my code like:
$(document).bind("pageinit", function () {
$("#submitButton").one("tap", function () {
save();
});
}
function save() {
$.ajax({method: "get",
url: baseUrl + "save?model=abcd&rand=" + randonNum(),
contentType: "application/json; charset=utf-8",
success: function (response) {
//do whatever
}
},
error: function (request, status, error, errorThrown) {
}
});
}