返回false后运行的Javascript函数

Question

In my code, when a select box is changed, a js function (ConfirmDelete) is called which asks the user if they are sure they want to change the select box. If the user selects no, it will return false and would normally stop the execution.

My problem is that I also have another AJAX/JS function defined after this that is waiting for the select box to be changed and if it is, it sends details to a php script which adds a record into a mysql database.

I'd like to know if there is anyway that I can stop the AJAX/JS code from running after a user has selected No.

The JS function

function ConfirmDelete()
{
  var x = confirm("Are you sure?");
  if (x)
  return true;
  else
return false;
}

The AJAX/JS function

$( ".dropdown" ).change(function() { 
    var request = new XMLHttpRequest();
var id = this.value;
var content = this.name;
request.open("POST", "samefile.php", true);
request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
request.onreadystatechange = function () {
if(request.readyState == 4 && request.status == 200) {
    var return_data = request.responseText;
    alert (return_data);

}
}

request.send("id="+id+"&content="+content);

window.location.reload();
window.location.reload();       
}

 );

The HTML Select box

<select class="dropdown" name="09:00-1-0-16-05-26" Onchange="return ConfirmDelete();">
<option class="co0es0sp1fd1oo0fs0" value="47">mike berry</option>
<option value="cancel-47">Cancel</option></select>

The order of the html is

• JS Function defined in header

• HTML code

• AJAX/JS Script tag after

Answer 1

The AJAX/JS function

$( ".dropdown" ).change(function() { 
    if(!ConfirmDelete()) return;  // right here, use this to confirm
    var request = new XMLHttpRequest();
var id = this.value;
var content = this.name;
request.open("POST", "samefile.php", true);
request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
request.onreadystatechange = function () {
if(request.readyState == 4 && request.status == 200) {
    var return_data = request.responseText;
    alert (return_data);

}
}

request.send("id="+id+"&content="+content);

window.location.reload();
window.location.reload();       
}

 );

Adding onchange event directly in HTML does not solve the problem. Use this instead;