EDIT: This is quite old, and ugly, don't do this. You should use callbacks: https://stackoverflow.com/a/5316755/591257
EDIT 2: See the fetch API
Had same problem, solved it this way, using a global var. Not sure if it's the best but surely works. On error you get an empty string (myVar = ''), so you can handle that as needed.
var myVar = '';
function isSession(selector) {
$.ajax({
'type': 'POST',
'url': '/order.html',
'data': {
'issession': 1,
'selector': selector
},
'dataType': 'html',
'success': function(data) {
myVar = data;
},
'error': function() {
alert('Error occured');
}
});
return myVar;
}